Log Cabin Memorial - Veterans 314th Infantry Regiment A.E.F.


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The Seventy-Ninth Division 1917-1918 Analytical Study in The Historical Section
The Army War College 1924 (Carlisle) Summary of Operations Sept.30 1918
Log Cabin Memorial - Veterans 314th Infantry Regiment A.E.F. - Use of Browning Automatic Rifle (BAR) by the 79th Division during WWI - Page 1
Log Cabin Memorial - Veterans 314th Infantry Regiment A.E.F. - Use of Browning Automatic Rifle (BAR) by the 79th Division during WWI - Page 2




MODEL OF 1918 
(Air Cooled) 






Document No. 853 
Office of the Adjutant General 


Document No. 853 
Office of the Adjutant General. 

WASHINGTON, September 7, 1918. 

The following confidential pamphlet, entitled "Technical Train- 
ing Handbook of the Browning Automatic Rifle, Model of 1918" 
(technical training series, prepared at the Infantry School of 
Arms, Fort Sill, Oklahoma), is published for the information and 
guidance of all concerned. 
(062.1 A. G. O.) 



General, Chief of Staff. 


Acting Adjutant General^ 





Introduction 6 

Organization of Class 7 

Subjects 8 

Detailed Method of Instruction 8 

Regulations Concerning Handling the Rifle 9 



General Remarks 1 1 

Lesson I. Nomenclature, Stripping, Assembling II 

Notes on Lesson I 12 

Name 12 

Type 12 

Ammunition 13 

Cooling System 13 

General Data 13 

Sequence of Stripping 14 

Notes on Stripping 14 

To Remove Firing Pin Without Stripping Gun 15 

Sequence of Assembling 16 

Notes on Assembling 16 

Lesson II. Stripping and Assembling Blindfolded 17 

Lesson III. Stripping and Assembling Trigger Mechanism. . . 17 

Notes on Trigger Mechanism 17 

Sequence of Stripping 17 

Assembling Trigger Mechanism j8 

Lesson IV. Magazines 19 

Notes on Magazine 19 

Lesson V. Spare Parts 20 

Notes on Spare Parts 20 



Lesson VI. Functioning 20 

Notes on Functioning 22 

General Remarks 22 

First Phase 22 

Action of gas 22 

The slide 23 

Unlocking 23 

Withdrawal of firing pin 24 

Extraction 24 

Ejection 24 

Termination of first phase 24 

Second Phase 25 

Action of recoil spring 25 

Feeding 25 

Locking 26 

Priming the cartridge 26 

Termination of second phase 26 

Action of Buffer 27 

Lesson VII. Functioning of Trigger Mechanism 27 

Notes on Trigger Mechanism 28 

Lesson VIII. Immediate Action (Classroom Instruction) .... 31 

Part II 31 

Immediate Action Table 33 

Notes on Im mediate Action 39 

Lesson IX. Immediate Action (on range) 39 

Notes on Stoppages 40 

Causes 40 

Analysis of Various Stoppages (as to cause) 41 

Lesson X. Care and Preservation 43 

Points to be Observed 43 


General Remarks 44 

Outline of Training of Automatic Rifle Section 44 

Instruction of the Individual 44 

Who Receives It 44 

Scope of Instruction 44 

Firing Positions 45 

Adjustment of the Sling 45 

Marching Fire 4^ 


Training of the Gun Team 49 

Scope of Training 49 

Formation of the Team 49 

Duties of the Members 50 

Loading 51 

Firing 51 

To Lie Down 52 

Marching Fire 52 

Field Cleaning 52 

The Squad 53 

Posts 53 

Drill 53 

Duties of the Corporal 53 

Deployments 53 

Continuous Fire 54 

Advancing 55 

The Section 55 


The purpose of this Handbook is to give methods of instruction 
to be used in teaching mechanism of the Browning automatic 
rifle, model of 1918, and to give an elementary drill of the rifle 
team and squad in so far as pertains to the handling and operation 
of the gun in firing. 

The method of instruction is that used in the automatic arms 
section of the Infantry School of Arms, Fort Sill, Oklahoma, and 
the drill is an adaptation to the Browning of the drill for the 
Chauchat rifle, as prescribed in the "Manual of the Automatic 
Rifle," War Department, April, 1918. 

It is contemplated that this book shall be used in conjunction 
with "Ordnance Pamphlet No. 1934," therefore, the construction, 
mechanism and care of the weapon is not dealt with in full herein. 
The information on these subjects pertains to methods of instruc- 
tion, with some additional notes not contained in "Ordnance 
Pamphlet No. 1934." 

The arrangement of subjects is according to sequence of in- 

It will be borne in mind that only the preliminary instruction 
of the automatic rifleman is covered here. 




1. For purposes of instruction the class will be divided 
into groups of three to four men (hereinafter referred to as 
teams). Each team will be assigned to a particular rifle and 
will work on that rifle throughout the remainder of the 
course. An assistant instructor (a sergeant or corporal here- 
inafter referred to as sergeant-instructor), will be assigned 
to not more than two of these teams and will supervise the 
same men throughout so as to maintain uniformity of in- 
struction. There will be at least two commissioned instruc- 
tors for each sixty men undergoing instruction. The purpose 
of such division is to fix the number of men assigned to one 
rifle so as to obtain maximum efficiency of instruction. More 
than four men working on one rifle and less than three will 
not give the best results. A sergeant-instructor cannot effi- 
ciently give detailed supervision to more than two teams, nor 
a commissioned instructor to more than fifty or sixty men. 
These remarks refer to the thorough instruction of a class in 

2. In the company the organization will be as follows: 
The automatic riflemen of the company will be combined in 
one class under two commissioned instructors. Each ser- 
geant will supervise his own section (as asistant instructor) 
and each corporal will act as sergeant-instructor for his own 

It is contemplated that the sergeants and corporals have 
had a thorough course of instruction prior to their men. 

3. A classroom will be provided with a blackboard, seats 
for entire class and one rifle table per team, sufficiently large 
to permit entire team to group around it while working on 
the rifle. 


4. Mechanism will be taught by subject in the following 

(1) Nomenclature, stripping and assembling of rifle, except 
trigger mechanism. 

(2) Nomenclature, stripping and assembling of trigger 

(3) Nomenclature, stripping and assembling of magazine. 

(4) Spare parts. 

(5) Functioning of gun proper (include magazine). 

(6) Functioning of trigger mechanism. 

(7) Stoppages and immediate action in classroom. 

(8) Stoppages and immediate action on range. 

(9) Care and preservation. 


5. No discussion of functioning should be permitted prior 
to the completion of stripping and assembling. Nomencla- 
ture will be taught during the instruction in stripping and 
assembling and reviewed throughout remainder of course. 

In each subject the following procedure will be observed: 

Introduction. The instructor will preface his instruction 
with a brief, general lecture leading up to the specific sub- 
ject in hand. 

Preparation. Instructor must prepare, ahead of time, all 
parts, etc., needed for day's work. 

Explanation-demonstration. The instructor will make a 
detailed explanation of the subject to be taught, illustrating 
or demonstrating his explanation as he goes along. This ex- 
planation-demonstration will be made to the class as a whole 
instead of being made by team or squad. This insures uni- 
form instruction for the entire class in the beginning of each 

Imitation. The teams will repair to their rifles and each 
man in turn will imitate the explanation-demonstration of the 

Introduction will be omitted. The other members of the 
team will stand by with handbooks and notebooks and check 
up any errors of the man reciting. The sergeant-instructor 
will supervise this work, correct errors, assist backward men 


and give detailed instruction in general. As men deem 
themselves qualified they will report to .their sergeant-in- 
structor for examination. He will require a perfect recita- 
tion before reporting a man as qualified to the senior in- 

Interrogation. Men will be quizzed on work in hand. 
Questions will be framed with a view to bringing out impor- 
tant points. 

6. Care must be taken to see that the sergeant-instructor 
does not hinder progress by trying to impress the men with 
how much he knows instead of instructing them. Whenever 
a sergeant-instructor demonstrates to one of his men the 
proper way to do a certain thing, he will always require the 
man actually to imitate him. There is sometimes a tendency 
for new sergeants to be continually demonstrating, thereby 
preventing their men from getting a chance at the rifle or the 
work in hand. This will be avoided. 


7. The following regulations are prescribed regarding the 
handling of the Browning automatic rifle: 

(1) Force will not be used. 

(2) This piece will not be stripped nor assembled against 

(3) The bore and working parts will be thoroughly cleaned 
and oiled whenever the piece is assembled. 

(4) The piece will be thoroughly cleaned and oiled at least 
Once a week in camp or garrison and daily in the field. 

(5) The magazine will receive the same care as the rifle. 
Every effort will be made to prevent bending or denting the 
magazines, being especially careful of the lips and magazine- 

(6) The filing or altering of shape or parts will not be per- 

8. The rifle is so constructed as to be taken apart and put 
together easily. Most parts are designed with a view to pre- 
vent wrong assembling. Where difficulty arises in stripping 
and assembling easily it is due to error on the part of the 


student and the use of force will only result in damage to the 

The practice of stripping and assembling against time 
serves no useful purpose and results in burring and damaging 
parts. Gradual skill develops as men become more familiar 
with the gun and lost motion is eliminated. Men should be 
taught in stripping to lay out parts in obvious sequence of 
assembling and should so thoroughly learn the gun that tak- 
ing it apart and putting it together is a matter of second 

Lubrication is necessary to the operation of the rifle. Dirt 
and extraneous matter will prevent it from functioning and 
do it damage. Instruction in care and preservation should 
be so thorough that cleaning and oiling become a matter of 

Unless strict supervision is exercised, inexperienced men 
and sometimes experienced men, will file or otherwise alter 
parts which do not need it. This results in damage to the 
rifle and usually fails to remedy trouble. Filing and altering 
of parts is sometimes necessary, but should never be done 
except by an expert, under direction of an officer competent 
to supervise the work. 

The use of rifles for instruction in mechanism is hard on 
them. This fact should be borne in mind and, in the company, 
after the completion of the first course in mechanism, only 
a limited number of rifles should be so used. 





9. Mechanism will be taught in the order given in lessons 
below. It may be necessary to devote several periods to a 
particular lesson. This will depend on the degree of intelli- 
gence of the class and the length of the period allotted. A 
ten-minute intermission at the end of each hour should be 
given if periods are longer than two hours. Each lesson 
will be mastered by the majority of the class prior to pro- 
ceeding to the next. When subject in hand allows, the pre- 
ceding lesson should be reviewed with the current one. For 
instance, nomenclature will be reviewed indefinitely by requir- 
ing every man to properly name each part he uses or men- 

10. It is contemplated that "Ordnance Pamphlet No. 1934" 
(handbook of the Browning machine rifle, model of 1918) 
be used in conjuction with this course. The notes following 
various lessons are intended to give the instructor supple- 
mental information. He will get additional data from inde- 
pendent research. His instruction, however, must not be 
at variance with "Ordnance Pamphlet No. 1934" and this 

11. Men will be encouraged to ask questions. They will 
not be permitted, however, to get ahead of the schedule. 


12. Introduction. The instructor will give a brief talk, in- 
troducing the rifle, wherein he will cover its type, caliber, 
characteristics and name such other points of general inter- 
est as he deems advisable. 

13. Explanation-demonstration. The instructor will go 
over the rifle, pointing out, naming and describing various 
parts externally visible. 


y This he will follow by slowly stripping the rifle, exclusive 
of trigger mechanism, holding up, naming and describing 
each part as he removes it. 

He will call attention to all cams, lugs, slots, profiles and 
springs, but does not at this time describe their function 
(bearing in mind the prohibition against discussing the func- 
tioning of the rifle prior to the completion of nomenclature, 
stripping and assembling). The instructor will assemble the 
piece acording to the same procedure. 

14. After this explanation-demonstration, the teams being 
assembled at their rifles, the instructor will describe, step by 
step, how to strip and assemble the rifle, naming and describ- 
ing parts as before. He will require one man at each rifle 
to imitate him as he finishes describing each step, the re- 
maining members of the team observing. Every man in the 
class will repeat names as called out by instructor. The in- 
structor will not allow any man to get ahead of his explana- 
tion in this stripping and assembling. Assistants will keep 
backward men up with the explanation (instructor must take 
care not to proceed too rapidly). 

15. Imitation. When this step-by-step explanation-imita- 
tion has been completed once the remaining members of the 
team will strip and assemble the piece, naming and describ- 
ing each part as it is removed and cleaning and oiling during 
assembly. The other members of the team will stand by with 
handbooks and correct errors of nomenclature. Sergeant- 
instructors will supervise and assist students and will see that 
mistakes are corrected as they are made. They will examine 
men whom they believe to be qualified and report to the 
senior instructor those who make a perfect recitation. 

16. Interrogation. The instructor will quiz class. 


17. The Browning automatic rifle, model of 1918 (air 
cooled), commonly referred to as the light Browning. 


18. The Browning automatic rifle is a shoulder weapon, gas 
operated, magazine fed and air cooled. It is an automatic 



19. It is chambered for caliber .30, U. S. ammunition, model 
of 1906. The magazine holds 20 rounds (there are special 
magazines which hold 40 rounds). 

Cooling System. 

20. It has no special cooling system nor device, the barrel 
merely being exposed to the air and the hand of the firer be- 
ing protected on the under side of the barrel by a large 
wooden forearm. Since the barrel soon becomes very hot, 
care must be taken to avoid touching it during firing or for 
five or ten minutes thereafter. 

General Data. 

21. (1) Weight of rifle, 15 pounds 8 ounces. 

(2) Weight of magazine, empty (20 rounds), 7 ounces (a 
total of 15 pounds 15 ounces). 

(3) Weight of magazine, filled (20 rounds), 1 pound 7 

(4) Length of barrel, 24 inches. 

(5) Sights, graduated up to 1,600 yards. 

(6) Caliber bore, 0.30 inch. 

(7) Gas port from muzzle, 6 inches. 

(8) Rate of fire, 500 shots per minute. 

(9) Weight of bullet, 150 grains. 

(10) Weight of powder, 47 grains. 

(11) Weight of shell, 198.5 grains. 

(12) Weight of cartridge (total), 395.5 grains. 

(13) Chamber pressure, 47,000 to 50,000 pounds per square 

(14) Muzzle velocity, 2,682 feet per second. 

(15) Habitual type of fire, semi-automatic. 

NOTE. This rifle has been fired, while marching, 148 
shots per minute, semi-automatic, at the infantry school of 
arms and 110 shots per minute, semi-automatic, from the 
shoulder, prone. The rates of fire, however, which appeared 
to give the best results were from 80 to 100 rounds per min- 
ute, semi-automatic marching fire and 50 to 60 shots per min- 
ute, semi-automatic aimed fire. 


Sequence of Stripping. 

22. (1) Cock the piece. 

(2) Gas cylinder tube retaining pin. 

(3) Gas cylinder tube (let down the mechanism easily). 

(4) Trigger guard retaining pin. 

(5) Trigger guard. 

(6) Recoil spring guide. 

(7) Hammer pin to right into hammer pin hole in re- 

(8) Operating handle. 

(9) Hammer pin. 

(10) Hammer. 

(11) Slide. 

(12) Bolt guide pushed to left. 

(13) Remove bolt, bolt lock and link. 

(14) Firing pin. 

(15) Extractor. 

Notes on Stripping. 

23. Lay the rifle on the table, barrel down, pointing to the 

The piece must be cocked in order that the gas cylinder 
tube may clear the gas piston and the gas cylinder bracket, 
female. After the gas cylinder tube has been removed it is 
necessary to release the tension of the recoil spring. A nat- 
ural tendency of the beginner is to snap the piece or to re- 
move the trigger guard before letting slide forward. This 
will result in damage and a special point must be made of 
easing the slide forward immediately after removing the gas 
cylinder tube. 

24. In stripping and assembling mechanism it will be noted 
that, unless tension in springs is released, the work will be 
more difficult, therefore, in the various steps of the opera- 
tions herein described, care is taken to avoid working against 
tension of springs. 

25. The recoil spring guide may be removed by placing 
right thumb on roughened surface of its head and turning it 
until the ends are clear of its retaining shoulders or it may 
be removed in a similar manner by using the index finger of 
the left hand and the middle finger of the right hand. This 
latter method is better, both in stripping and assembling, for 
men who have not powerful hands. 


26. Hammer pin holes on the receiver and operating han- 
dle may be easily lined up by: 

(1) Pulling the operating handle a few inches to the rear of 
the raised shoulders on the operating handle ribs. 

(2) Grasping slide with the left hand and pushing on the 
rear end with the right hand until the plunger pin just rides 
up on the rear end of the flat surface of the raised shoulders 
on the operating handle ribs. 

Another method is to pull the operating handle to the 
rear, as described above, insert the point of the recoil spring 
guide in the hole on the operating handle with the right hand, 
pressing against the hammer pin and pull the slide forward 
with the left hand. The recoil spring guide will push ham- 
mer pin through its hole in the receiver as the hammer pin 
registers with latter. Care must be taken that all forward 
movement of slide comes through pulling slide with the left 
hand, the right hand being used only to press the hammer 
pin out. 

27. In removing the slide take care to avoid striking gas 
piston or rings against gas cylinder tube bracket (female) and 
also to see that the link is swung back so that the slide will 
clear it. 

28. The bolt guide must be forced out enough to allow the 
bolt and bolt lock to be lifted out of the receiver. If the bolt 
guide spring is strong the rim of a cartridge may be inserted 
between the outside of the receiver and the exterior portion 
of the bolt guide, thus giving a lever with which to hold the 
bolt guide out. 

To Remove Firing Pin Without Stripping Gun. 

29. (1) Remove trigger mechanism. 

(2) Lock slide in rear position with extra firing pin, head 
against operating handle, point in hammer pin slot in re- 

(3) Lock bolt guide out with rim of cartridge. 

(4) Incline barrel up at angle of 45 degrees, magazine 
opening down. 

(5) Buckle bolt lock, bolt and link assembly down, firing- 
pin will drop out. 


Sequence of Assembling. 

30. (1) Extractor. 

(2) Firing pin. 

(3) Bolt, bolt lock and link. 

(4) Slide. 

(5) Hammer. 

(6) Hammer pin (far enough to register all holes). 

(7) Operating handle. 

(8) Hammer pin, fully seated. 

(9) Recoil spring and guide. 

(10) Trigger guard. 

(11) Trigger guard retaining pin. 

(12) Cock the piece. 

(13) Gas cylinder tube. 

(14) Gas Cylinder tube retaining pin. 

(15) Ease the slide forward. 

(16) Oil and test the piece. 

Notes oh Assembling. 

31. Before inserting slide, see that link is thrown clear back 
so that slide will clear. Slide is inserted so that the sear 
notch is visible when looking into the receiver from the 
trigger side. 

The hammer is inserted with its convex surface to the 
rear and its flat surface toward the trigger mechanism open- 
ing in the receiver. 

32. To insert the hammer pin, move slide forward and line 
up hammer pin holes in link, hammer, slide and receiver, by 
inserting recoil spring guide through slot in side of receiver. 
The hammer pin is not pushed clear through until the operat- 
ing handle has been moved all the way home. 

33. Be careful to put the operating handle on with the 
handle end forward. If it is assembled, with the reverse end 
forward, an expert mechanic will be required to remove it. 
After the operating handle has been pushed home the ham- 
mer pin is then fully seated and the slide pulled forward. 

34. In assembling the trigger guard to the piece see that 
no pins are projecting from its sides. Seat slot, in its rear 
end, on flange in rear end of opening in receiver, then press 
back and down on forward end of trigger guard until it 
hinges into place. See that holes are properly registered be- 
fore inserting trigger guard retaining pin. 


35. Cock the piece by pushing the gas piston to the rear. 
Take care to register gas cylinder tube and piston on assem- 
bling same and avoid burring gas cylinder tube brackets, 
male and female. 


36. Teams at gun tables. Each man in turn, blindfolded, 
strips and assembles the gun. The sergeant-instructor 
watches him to prevent wrong assembly or forcing of parts. 
He may be given assistance in event he cannot proceed other- 
wise. If he calls for any part, by its right name, same will 
be handed him. 

The other members of the team not blindfolded will have 
various parts put in their hands while same are behind back 
and will name parts by feel. Extraneous pieces of metal may 
be introduced in this latter exercise. 

The purpose of this instruction is to so train the soldier as 
to enable him to replace breakages and reduce stoppages in 
the dark. 



37. Follow procedure, outlined in lesson I, instructing in 
the trigger mechanism, i.e.: 

(1) Explanation and demonstration by instructor. 

(2) Explanation, step-by-step, by instructor and imitation, 
step-by-step, by one student in each team. 

(3) Imitation of (1) by each of remaining students, stu- 
dent reciting being checked as described in lesson I. 

(4) Interrogation by instructor. 

Sequence of Stripping. 

38. (Not to be done in the fi,eld except to replace break- 

(1) Sear spring (insert handle of trigger guard retaining 
pin under sear spring, above connector stop, pry up, press- 
ing against sear spring with thumb and pulling to the rear). 


(2) Trigger pin. 

(3) Trigger and connector. 

(4) Sear pin (release the pressure on sear pin by stand- 
ing trigger mechanism vertically on flat forward end, levering 
sear carrier forward with recoil spring guide inserted just in 
rear of counter-recoil spring. Then push the sear pin out 
with the point of a cartridge). Pressure on tail of sear 
causes sear pin to bind between sear carrier and sear. 

(5) Sear. 

(6) Sear carrier and counter-recoil spring. 

NOTE. Sear carrier must be pried up so as to clear change 
lever spring. 

(7) Change lever spring (change lever spring is removed 
by prying bent over rear end out of its seat with rounded 
end of sear spring and moving change lever from front to 
rear. When it is clear of the change lever it is pushed the 
rest of the way out by pressing with the thumb against the 
sear stop). 

(8) Change lever. 

(9) Ejector (depress ejector lock with point of cartridge, 
hold thumb in front of magazine catch spring to prevent its 
loss and slide ejector out). 

(10) Magazine catch spring. 

(11) Magazine catch pin. 

(12) Magazine catch. 

(13) Magazine release. 

Assembling Trigger Mechanism. 

39. Sequence of assembling is in reverse order of stripping. 

Notes on Assembling Trigger Mechanism, 

40. The following points are worthy of note: It is easier 
to seat the magazine catch spring if the ejector is moved 
down until it is flush with the magazine catch spring before 
attempting to compress the latter. 

41. In assembling change lever spring first insert the 
ears in slots in trigger guard and push spring forward a 
slight distance, then insert the rounded end of sear spring 
between the rear end of the trigger guard and the change 
lever spring. By prying up with the sear spring and, at the 
same time, pressing against sear stop with thumb and 
ratcheting change lever from rear to front the change lever 


spring is easily seated. Sear carrier and counter-recoil spring 
are assembled to trigger mechanism by inserting counter- 
recoil spring guide in its seat, then using the recoil spring 
guide as a lever in sear pin hole, prying the sear carrier for- 
ward until its rear end is held by the ears on the change 
lever spring. The sear is now inserted and the recoil spring 
guide forced through so as to register the holes in the sear, 
sear carrier and trigger guard for the sear pin, which is forced 
in by pressing it against a block of wood, thus- forcing the 
recoil spring guide out. 

42. In assembling the connector note that its toe points 
to the rear and that its head is in rear of the connector stop 
(rear is the direction away from the ejector toward the sear). 

43. Be especially careful to see that the outside prongs of 
the sear spring rest on their seats on the sear and that the 
middle prong rides freely in the slot formed by the walls of 
the sear carrier. If this middle prong rests on one of these 
walls, instead of riding freely between them, the trigger 
mechanism will not function when the barrel is inclined below 
the horizontal. 


44. Following the procedure outlined in Lessons I and III, 
the instructor will teach nomenclature, stripping, assembling 
and loading of the magazines. 

Notes on Magazines. 

45. Loading exercise will be conducted with dummy ammu- 

46. The men must be taught that the magazines require the 
same care and preservation as the rifle. They must not be 
allowed to become dirty. Dented magazines will cause mal- 
functions. The greatest possible care should be taken to 
prevent any damage whatever being done to the lips of the 
magazine or to the notch for the magazine catch. 

Sequence of Stripping. 

(47) (Not to be done in the field). 

(1) Magazine base (raise rear end of magazine base until 
indentations thereon are clear, then slide to the rear). 

(2) Magazine spring. 

(3) Magazine follower. 


48. Assemble in reverse order, viz.: Follower, spring and 
base. Note that bent-over end of follower and eye of spring 
work against inside of rear (notched) end of magazine. 


49. The nomenclature of the spare parts kit will be taught 
according to the principles hereinbefore enunciated. This in- 
struction will include the proper method of packing the spare 
parts kit. It will also include instruction in the contents of 
the gun box. 

Notes on Spare Parts. 

50. The importance of knowing what is and what is not 
carried as a spare part should be impressed on all automatic 

It is essential to know where to find any spare part that 
may be required. 

All spare parts must be given their proper names, the use 
of other names is forbidden. 

A list of deficiencies should be kept inside each gun box. 

Spare parts must be kept slightly oiled. 

The necessity of checking spare parts whenever oppor- 
tunity offers must be emphasized. 

Breakages and losses must be reported immediately. 

Noncommissioned instructors will check their own spare 
parts at the beginning and end of the instruction and will 
render a report showing deficiencies. 

Worn or defective parts should not be kept in the spare 
parts box. 

Where any rifles are kept in reserve care should be taken 
to see that they are in the same condition of readiness for 
action as those to be used in the firing line. They should not 
be utilized as a source for obtaining spare parts. 


51. Introduction. The instructor will give a brief lecture, 
explaining the difference between recoil operated and gas 
operated guns, that most automatic weapons have some sort 
of a cooling system and the reasons thereof (it will be 
noted that there is no special device for cooling the Browning 


automatic rifle but that the barrel is exposed as much as pos- 
sible to the air). He will further explain that all automatic 
weapons must have mechanical means for performing the 
following functions: Extraction, ejection, feeding, locking 
breech while there is high pressure in the bore and priming 
the cartridge. He will define and illustrate any mechanical 
terms which he uses. For instance "to cam" is to change the 
direction of motion of a part by means of a cam. Instructor 
may illustrate this by showing how the bolt supports act on 
the bolt lock during the operation of locking. 

52. The operations of extraction, ejection, etc., are per- 
formed by various cams, lugs and springs and the energy 
necessary to perform this work and overcome friction in the 
rifle is derived from the explosion of the powder in the 

He will explain that these operations have a certain se- 
quence in the various guns and that some of them are con- 
current, that in the Browning the men will be expected to 
learn and understand thoroughly the various operations sep- 
arately and then to visualize them as they are actually hap- 
pening in the rifle during firing. In other words, that the 
soldier must be able to "see" the relative position of all the 
parts, at any time, of the operation of the rifle. 

53. Explanation-demonstration. This explanation-demon- 
stration will be illustrated with an assembled rifle, parts of 
rifles and drawings, in the following order: 

Operation in general terms (as given on page 9, Ordnance 
Pamphlet No. 1934). 

Definition of the two phases of action (as given below, 
paragraph 57). 

First Phase. 

(1) Action of gas. 

(2) Slide. 

(3) Unlocking. 

(4) Withdrawal of firing pin. 

(5) Extraction. 

(6) Ejection. 

(7) Termination of first phase. 

Second Phase. 

(1) Action of recoil spring. 

(2) Feeding. 

(3) Locking. 

(4) Priming. 

(5) Termination of second phase. 

Action of the Buffer. 

54. Imitation. As outlined in lessons I and III. 

55. Interrogation. By instructor. 

General Remarks. 

56. It is not desired to have the student memorize the dis- 
tances given below. He must have, however, an approxi- 
mate idea of these distances; for instance, he should under- 
stand that the backward travel of the bolt has been very lit- 
tle when the bolt lock is drawn completely down but, on the 
other hand, that the slide has moved a considerable distance. 

57. The functioning of the Browning automatic rifle is 
divided into two phases, based on the natural operation of the 
mechanism when a shot is fired. These two phases are the 
backward and the forward action. In making this division 
we assume, as a starting or reference point, the priming of a 
cartridge in the chamber. 

Action of Gas. 

58. A cartridge having been primed, the bullet, under the 
pressure of the expanding powder gases, travels through the 
barrel and when it reaches a point 6 inches from the muzzle 
it passes a port in the bottom of the barrel. The barrel pres- 
sure, which at this instant is still very high, seeks this first 
natural vent. Registered with the barrel port are other similar 
ports in the gas cylinder tube bracket, gas cylinder tube and 
gas cylinder. The port in the gas cylinder is the smallest 
and serves to throttle the barrel pressure. The ports in the 
gas cylinder lead radially into a well about ,12 of an inch 
in diameter in the head of the gas cylinder. The throttled 
barrel pressure is conducted through this well to the gas 
piston plug. This pressure acts on the piston a very short 
time, namely, the time it takes the bullet to travel the 6 inch 
distance from the barrel port to the muzzle. Its effect is that 
of a sudden severe blow on the piston plug. Under the in- 
fluence of this blow the gas piston is driven to the rear and 

carries with it the slide to which it is assembled. When the 
piston has travelled about .58 of an inch backward the bear- 
ing rings on its head, also the gas piston plug, pass out of 
the cylinder. The gas expands around the piston head and 
into the gas cylinder tube and is exhausted through six port 
holes in the tube just in rear of the gas cylinder tube bracket. 
The gas is prevented, in a large measure, from travelling back 
through the gas cylinder tube by two rings on the piston, .62 
of an inch apart and 1.25 inches from the piston head. These 
rings also serve as bearings to hold the front end of the pis- 
ton in the center of the gas cylinder tube after the piston 
head has passed out of the gas cylinder. 

The Slide. 

59. Having traced out the action of the gas we will now go 
back and take up the action of the mechanism as it moves to 
the rear. The first and immediate result of the backward 
movement of the slide is the beginning of the compression 
of the recoil spring, thereby storing energy for the forward 


60. The hammer pin is slightly in advance of the link pin, 
about .19 of an inch. The center rib of the hammer is against 
the head of the firing pin. When the slide begins its motion 
to the rear it imparts no motion whatever to the bolt and 
bolt lock. The slide moves back .19 of an inch and its only 
effect during this travel is to carry the hammer from the 
firing pin and the hammer pin directly under the link pin. 
At this point the unlocking begins, the link revolves forward 
about the hammer pin drawing the bolt lock down and to the 
rear. The motion of the lock and bolt, which is zero at the 
instant the hammer pin passes under the link pin, accelerates 
from this point until the slide has travelled 1.19 inches, at 
which point the lock is drawn completely down out of the 
locking recess and away from the locking shoulder of the 
receiver. It is now supported in front on the bolt sup- 
ports -and the front upper shoulder of the link has revolved 
forward and is against the locking shoulder of the bolt lock. 
These two influences prevent the bolt lock revolving down 
below the line of backward travel of the bolt. 


Withdrawal of Firing Pin. 

61. As the bolt lock revolves down from its locked position 
a cam surface in a slot in the rear bottom side of the bolt 
lock comes in contact with a similar cam surface on the firing 
pin lug and cams the firing pin from the primer. 


62. The backward motion of the bolt begins when the bolt 
lock has been drawn down so that the circular cam surface 
on its under side is operating on the rear shoulders of the 
bolt supports. This produces a strong lever action which 
slowly loosens the cartridge case if stuck in the chamber. 
The backward travel of the bolt has been slight, only .17 of 
an inch when the firing pin is withdrawn, its travel is .35 of 
an inch when the bolt lock is drawn completely down. From 
this point the bolt moves to the rear, drawn by the bolt lock 
and link, with the same speed as the slide and carries with it 
the empty cartridge case, which is held firmly in its seat on 
the face of the bolt by the extractor. The extractor is on 
the upper righthand side of the bolt next to the ejection 
opening in the receiver. A slot cut in the left side of the 
bolt lock near the back end passes over the bolt guide, which 
supports the bolt lock and bolt when they are in the cocked 


63. When the slide reaches a point .22 of an inch from the 
end of its travel, the base of the cartridge case strikes the 
ejector, which is on the left side of the feed rib of the bolt 
and opposite the extractor. This action causes the cartridge 
case to be pivoted with considerable force about the ex- 
tractor as a pivot and through the ejection opening, in the 
receiver. The front end of the cartridge case passes first 
out of the receiver and is pivoted backward so that it strikes 
the receiver at a point about 1 inch in rear of the ejection 
opening. It rebounds from the receiver toward the right 

Termination of First Phase. 

64. The backward motion is terminated by the rear end 
of slide striking the buffer at the back end of the receiver. 
The slide moves forward .10 of an inch, after striking the 


buffer, under the action of the recoil spring, but if the sear 
nose is not depressed it engages the sear notch on the slide 
and the piece is cocked for the next shot. 

NOTE. It was seen that the motion of the bolt and lock 
and link mechanism began slowly at first and did not attain 
the speed of the slide until the slide had travelled 1.2 inches 
backward. This is a very important and good characteristic 
of the rifle because it relieves the mechanism of th*e excess 
strain which it would have if those parts were started sud- 
denly at the instant the gas impinges on the piston. Another 
very important result of this characteristic of the design is 
the delaying of the opening of the chamber an instant of time 
to allow the high barrel pressure to decrease. 

Action of Recoil Spring. 

65. The sear nose is depressed, disengaging the sear and 
the slide moves forward under the action of the recoil spring. 
The link pin is slightly below a line joining the bolt lock pin 
and the hammer pin, therefore, as the slide starts forward, 
the joint at the link pin has a tendency to buckle downward. 
It is prevented from doing this by the tail of the feed rib of 
the bolt, which extends backward under the bolt lock, also 
principally by the upper front shoulder of the link being in 
contact with the locking surface of the bolt lock. Since the 
joint cannot buckle, the entire mechanism moves forward 
with the "slide. When it has travelled .27 of an inch the front 
end of the feed rib impinges on the base of the cartridge 
which the magazine spring and lips are holding up in its 


66. The cartridge is carried forward about .27 of an inch, 
when the nose of the bullet strikes the bullet ramp or guide 
on the breech of barrel and is deflected upward towards the 
chamber. This action also guides the front end of the car- 
tridge from under the magazine lips. The base of the car- 
tridge approaches the center of the magazine, where the lips 
are cut away and the opening enlarged, and at this point is 
forced out of the magazine by the magazine spring. The 
base of the cartridge slides across the face of the bolt and 
under the extractor. . Should the cartridge fail to slide 


under the extractor the extractor will snap over its head 
when the bolt is in the forward position. When the 
cartridge is released by the magazine the nose of the bullet 
is so far in the chamber that it is guided by the chamber 
from this point on. 


67. When the slide is 1.19 inches from its forward position 
the circular cam surface on the under side of the bolt lock 
begins to ride over the rear shoulders of the bolt supports 
and the rear end of the bolt lock is cammed upward. The 
link pin passes up above a line joining the bolt lock pin and 
hammer pin. f ne joint at the link pin now has a tendency 
to buckle upward and the bolt lock, being opposite the lock- 
ing recess in the receiver, is free to and does, pivot upward 
about the bolt lock pin. The link revolves upward about the 
hammer pin, forcing the bolt lock up and a rounded surface 
on the bolt lock, just above the locking face, slides over the 
locking shoulder in the receiver, giving the lock a lever 
action which forces the bolt home to its final position. The 
two locking surfaces on the bolt lock and the receiver regis- 
ter as the hammer pin passes under the link pin. 

Priming the Cartridge. 

68. The lug on the firing pin is buried in the slot in rear 
of the bolt lock at all times except when the bolt lock is 
against the locking shoulder of the receiver, therefore the 
firing pin is locked away from the primer during all the 
backward and forward motion of the bolt. When the ham- 
mer pin passes under the link pin the firing pin has just been 
released by the bolt lock. The slide and hammer move for- 
ward about .11 of an inch further and the center rib of the 
hammer strikes the head of the firing pin, driving it forward 
and priming the cartridge. 

Termination of Second Phase. 

69. The front end of the slide strikes a shoulder at the 
rear end of the gas cylinder tube, which terminates the for- 
ward motion. The forward motion is not terminated by 
the hammer on the firing pin. This can be seen by exam- 
ining the head of the firing pin when the gas cylinder tube is 
assembled to the receiver and the bolt mechanism is in the 


forward position. The firing pin has still about .06 of an 
inch clearance from its extreme forward position. 

NOTE. The locking shoulder of the receiver is inclined 
forward. Its surface is normal or perpendicular to a line 
joining it and the bolt lock pin, therefore the shock of the 
explosion of the cartridge is squarely against it. Attention 
is also called to the fact that the speed of the bolt mechan- 
ism is slowed down gradually from the instant the joint at 
the link pin is broken upward, until the hammer pin passes 
under the link pin, when its speed is zero. 

Action of the Buffer. 

70. The buffer system consists of a tube in which are placed 
successively, from front to rear, the buffer head, a brass fric- 
tion cup with concave interior and split to allow it to spring. 
A steel cone to fit into the cup; four of these cups and cones 
are placed one after the other or in series. Next is the buf- 
fer spring and finally the buffer nut, which is screwed into 
the end of the tube and forms a seat for the spring. 

The Action. 

71. The buffer head is struck by the rear end of the slide, 
this forces the cups over the cones and causes them to ex- 
pand tightly against the tube and consequently produces con- 
siderable friction as the cups move back and compress the 
buffer spring. Thus the rearward motion of the slide is 
eased up gradually and there is practically no rebound. The 
spring causes the buffer head and friction cups and cones to 
return to their original positions. 


72. Preparation. Instructor and each team have a stripped 
trigger mechanism before them. 

73. Explanation-demonstration. Instructor describes parts 
and explains functioning in detail according to method in 
notes below. 

74. Imitation. Students describe parts and explain func- 
tioning as outlined in lesson I. 

75. Interrogation. Instructor quizzes students. 


Notes on Trigger Mechanism. 

76. The trigger mechanism has three settings: 

(1) Automatic (A). When so set the sear is held de- 
pressed as long as the trigger is pulled and the piece will 
continue firing until the magazine is emptied. 

(2) Semi-automatic (F). When so set the sear is de- 
pressed, thereby disengaging the sear and sear notch when 
the trigger is pulled, but the mechanism is so constructed 
that the sear rises and engages in the sear notch when the 
slide comes back again and the sear and sear notch will not 
disengage until the trigger is fully released and then pulled. 
With this setting the piece fires one shot, ejects the empty 
cartridge and cocks itself for each pull and release of the 

(3) Safe (S). When so set the sear cannot be released 
from the sear notch by pulling the trigger. 

77. The action of the trigger mechanism is taken up in 
phases and should be followed through on the mechanism 
itself as the explanation proceeds. Have the trigger guard 
stripped completely. Study the shape of the change lever 
and note the following: 

(1) It is a bar about .25 of an inch in diameter. 

(2) It has 3 shallow longitudinal slots cut on top of the 
bar, as the handle is held vertically. 

(3) The side of the bar is slotted in such a way as to leave 
a little tongue of metal in the center and at the lower edge 
of the slot. 

78. To assemble the change lever and spring to the trigger 
guard. Note that the toe of the change lever spring is 
seated in one of the longitudinal slots on the change lever 
and that as the lever is turned from one position to another 
it seats in the other slots. The only function of the spring 
and the longitudinal slots is to hold the change lever in the 
position in which it is placed. 

79. To assemble the trigger and pin to the guard. Turn 
the change lever to rear or safe position. Note that in this 
position the slot is turned slightly upward and that the full 
surface of the bar is on the bottom. Pull the trigger. Note 
that the rear top end of the trigger is slotted longitudinally 
and that the metal on each side of the slot forms two shoul- 
ders that come up against the bottom of the change lever bar. 


80. Push the change lever over to the vertical position, 
which is the automatic setting. Pull the trigger just as be- 
fore and note that the slot in the change lever is turned to 
the front and that the two shoulders of the trigger, which be- 
fore engaged the full surface of the change lever bar, now 
are free to pass up into the slot of the change lever, also 
that the little tongue of metal on the bottom of the change 
lever slot passes through the longitudinal slot in the end of 
the trigger. 

81. Push change lever forward or to single-shot position. 
Note that now the slot is turned partially down and that 
when the trigger is pulled the front end of the trigger passes 
up into the change lever slot, also that the little tongue of 
metal in the bottom of the change lever slot is now turned 
back and does not pass through the slot in the end of the 
trigger as it did in the automatic position. 

82. Observe the shape of the connector. Its lower end is 
shaped like a boot with a toe and heel. It has a flat sur- 
face that slopes down and toward the front from the head 
(sear spring ramp). In rear of the head the profile extends 
straight downward for about .12 of an inch, then slopes 
slightly to the rear for .12 of an inch (sear carrier ramp). 
This last slope is used in a cam action to be explained later. 
Note the narrow flat top surface of connector. Its function 
is to raise forward end of sear until cammed out from under 

83. Place the connector on the connector pin and change 
lever on the safe position, pull the trigger and note that the 
connector is not raised for the obvious reason that trigger 
itself cannot be raised because the change lever bar is in its 
way. Turn change lever to automatic position, pull the 
trigger and note that the head of the connector is raised and 
held in a vertical position and cannot be tipped forward. 
The tongue on the change lever engages the toe of the con- 
nector as the trigger is pulled and holds the connector up- 

84. Turn the change lever to single shot position, pull the 
trigger and note that the tongue on the change lever does 
not now engage the toe of the connector and that the head 
of the connector can now be tipped forward. 

85. Observe now the cross pin on the sear carrier, called 
the connector stop, also that just in rear of the connector 


stop and on the under side of the sear carrier is an inclined 
surface sloping upward in the metal which joins the two sides 
of the sear carrier. This surface has a cam action with the 
above mentioned cam surface on the connector. 

86. Completely assemble the trigger mechanism. Note that 
the center leaf of the sear spring presses on the front slop- 
ing surface of the connector and tends to press the head of 
the connector backward. Put change lever on safe and pull 
trigger. Note the head of connector is not raised above the 
sear carrier for reasons given previously. Therefore, the 
sear nose is not depressed and hence the safe position. 
Change over to the automatic position and pull the trigger, 
the head of the connector is raised and held in the vertical 
position, thus depressing the sear nose and holding it in this 
position, which obviously gives automatic fire as long as 
there are cartridges in the magazine. 

87. The tongue on change lever tends to hold connector 
vertically and the ramp on sear carrier tends to cam con- 
nector forward. The forces on connector exerted by these 
two parts are opposed, hence trigger mechanism is locked 
when trigger has been pulled enough to release slide. 

88. Put change lever on single shot setting, pull trigger 
slowly. Note that at first the head of the connector rises and 
thereby depresses the sear nose which allows the slide to go 
forward and fire a shot. Continuing the squeeze of the 
trigger, the previously mentioned cam surface on the con- 
nector comes in contact with the cam surface of the sear 
carrier and the head of the connector is cammed forward 
against the pressure of the center leaf of the sear spring. 
The connector disengages the front arm of the sear and the 
two outside leaves of the sear spring depress it and the 
sear nose is thereby raised up in the path of the slide and 
engages the sear notch when the slide moves back, thus 
allowing only one shot to be fired. When the trigger squeeze 
is released the center leaf of the sear spring presses the 
head of the connector downward and forward under the 
front arm of the sear so that when the trigger is pulled 
again the action is repeated and single shot is fired. 

89. In the semi-automatic position the connector stop pre- 
vents the head of the connector being tipped so far forward 
that the sear spring cannot push it back in place when the 
trigger is released. The only function of the change lever 


in the semi-automatic position is the limiting of the upward 
travel of the trigger when its upper rear shoulders strike the 
top of the slot in the change lever, which in this position is 
turned down. 

(Classroom Instruction). 

90. Introduction. The instructor will give definition of 
immediate action (the automatic and instinctive application 
of a probable remedy for a stoppage, based on the position 
of the hammer pin, as determined by pulling back operating 

91. Demonstration-explanation. The instructor will dem- 
onstrate the four positions of the hammer pin and how to 
determine its position by pulling back the operating handle 
until it strikes the hammer pin. 

92. Each member of team is required to learn how to de- 
termine the position of the hammer pin by setting the slide 
in the four positions (recoil spring removed and piston held) 
and then by placing thumb in rear of trigger guard and fin- 
gers on operating handle, squeezing operating handle back 
until it strikes the hammer pin. Students will then be re- 
quired to state in which position mechanism was stopped. 

Part Two. 

93. (1) Under direction of instructor, sergeant-instructor 
prepares the various stoppages for the first position of ham- 
mer pin. 

(2) Explains the immediate action. 

(3) Requires each member of team to perform immediate 
action, criticizing performance. 

(4) Quizzes team. 

Each phase of the first position is taught until all are pro- 
ficient before teaching next phase. 




NOTE. The operating handle is shown in the rearmost 
phase in each position. In the first position the movement 
of the operating handle is zero. Stoppages for the various 
positions may allow the operating handle to strike the ham- 
mer pin anywhere within limits shown by brackets and ver- 
tical lines above. 


Explanatory Notes. 

94. The following table will be utilized in teaching imme- 
diate action, both in classroom and on the range. In class 
work stoppages will be set up, not in the student's sight and 
when he inspects the gun he will find the hammer pin and 
the rifle in such condition as would result if that stoppage 
occurred during actual firing. On the range these stoppages 
will be induced so as to occur during firing. 

95. Column 1 describes the four positions of the operating 
handle (when drawn back until it strikes the hammer pin 
where same is fixed by stoppage). Plates show rearward po- 
sition of operating handle for each of the four positions. 
These positions, which afford a ready indication of the cor- 
rect immediate action to be performed, must be recognized 
clearly before instruction proceeds. When this has been 
accomplished the soldier will be required to learn what these 
four positions indicate. 

96. Column 2 gives a detailed description of the immediate 
action to be performed by the firer as soon as he has de- 
termined the position of the hammer pin by drawing back 
the operating handle until it strikes the hammer pin. It will 
be noted that in all four of the positions the first stage of 
the immediate action is to pull back the operating handle 
and examine what conies out of the chamber. 

97. Column 3 deals with the probable causes of these stop- 
pages. It is of the utmost importance that the instructor 
does not proceed to this stage until he is assured that every 
immediate action can be correctly and immediately performed 
without the slightest hesitation. 

98. A thorough knowledge of the causes of temporary stop- 
pages will not only afford a practical knowledge of the work- 
ing of the rifle, but will also be an aid in the discovery of 
the cause of any unusual break-down which may occur. 

99. It is not wholly necessary to teach the gunners and 
carriers the method of "setting-up" stoppages but all in- 
structors and assistant instructors should thoroughly under- 
stand this phase. 



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100. Stoppages in the automatic action of the rifle during 
firing may be classed under two main headings: 

(1) Temporary, which are due to: 

(a) Failure of some part of rifle of which a duplicate is 

(b) Faulty ammunition. 

(c) Neglect of points before or during firing. 

(d) Ignorance on part of rifle team. 

(2) Prolonged, which are due to failure of some part that 
cannot, as a rule, be remedied by the team under fire or 
without skilled assistance. These necessarily put the gun 
Out of action for a more or less prolonged period. 

Upon the knowledge and training of the automatic riflemen 
depends the rapidity with which temporary stoppages can be 

It is essential that stoppages be prepared accurately. 


(On Range). 

101. Stoppages will be set up on range, using prepared 
magazines, ammunition and parts so as to cause them to occur 
during firing. 

Student will fire. When stoppage occurs he will call first 
position, third position or whatever position he thinks it may 
be. If he calls the correct position the sergeant-instructor 
will command immediate action, whereupon the student exe- 
cutes the necessary immediate action. 

102. When the student has been thoroughly grounded in 
immediate action the various stoppages will be set up and 
he will be required to perform the necessary immediate action 
in each case without naming it and without command, as 
soon as the stoppage occurs. This in order to acquire speed 
and accuracy. 



103. Stoppages are caused by the following: 

(1) Dire (natural fouling incident to firing and also to 
careless cleaning). 

(2) Insufficient oil (from failure to oil and because of oil 
burning up during firing). 

(3) Extraneous matter in working parts (due to poor clean- 
ing, brass chipped off from cartridges, breakages, blown 
primers, etc.). 

(4) Improper assembly of rifle (gas ports not registered, 
middle prong of sear spring riding on one wall of sear car- 
rier, etc.). 

(5) Breakages (due to wrong assembly, oversize or under- 
size parts, burrs, incorrect heat treatment, overheating of 
parts incident to firing, etc.). 

(6) Burred parts (due to use of force, grit, etc., improper 
assembly, extraneous matter in mechanism). 

(7) Magazine troubles (due to bent or dented magazines, 
worn magazine catch notch, extraneous matter as blown 
primer between lips of magazine and top cartridge). 

(8) Faulty ammunition (dented cartridges, failure of 
primer or charge, etc.). 

(9) Excessive play in parts (due to wear, to stripping parts 
not supposed to be stripped, as removing barrel from re- 
ceiver, for instance). 

10. Ruptured cartridges (due to excessive head space). 
Headspace is the distance between the face of the bolt and 
the head of a standard steel test cartridge. If this distance 
is excessive, then when the cartridge case is forced against 
the walls of the chamber by the high pressure, incident to 
explosion of charge, the head of the cartridge is driven to 
the rear since it is not properly supported by Jhe bolt. This 
results in rupture about ^ inch from the base of the cart- 
ridge. In effect the action is the same as if the chamber 
gripped the cartridge case and the head of the cartridge for 
about Y-2 inch were free to move; since the chamber pressure 
is 50,000 pounds per square inch, it can be seen why the case 
is ruptured. If the chamber is dirty and there is any ex- 
cessive headspace, ruptured cartridges are sure because the 
case is "gripped" with more friction. By cleaning the cham- 


her thoroughly and oiling the cartridges this stoppage will 
be corrected until the headspace becomes very excessive (the 
case is never pulled apart by extractor). 

Analysis of Various Stoppages (As To Cause). 
First Position. 

104. Failure to feed. Obstruction (usually a blown primer), 
between lips of magazine and top cartridge, causes failure 
of presentation of a cartridge to feed rib and the bolt goes 
home on an empty chamber. Same result occurs when the 
magazine catch notch becomes so worn as to permit the 
magazine to drop down slightly and also when magazine 
catch breaks. 

105. Misfire. Faulty primer or charge will cause a misfire 
as will also a broken or short firing pin. Frequently the be- 
ginner will mistake a misfire due to an obstruction between 
the face of the bolt and the breech for one due to a broken 
firing pin. He should remember that the latter is a first posi- 
tion stoppage and the former a second position stoppage. A 
misfire due to a broken firing pin will not show any indenta- 
tion on the primer. The second position stoppage almost 
invariably shows a slight indentation. 

106. Failure to extract. A stoppage in the first position 
with an empty case in the chamber is due to insufficient gas. 
Insufficient gas in turn may be due to the gas ports not being 
properly registered or being partially clogged, or to exces- 
sive friction because of lack of oil and dirty chamber. When 
there is sufficient gas to properly function the rifle, but the 
chamber is very dirty, the bolt will be driven back with such 
force that the extractor will cut through the rim of the cart- 
ridge and a third position stoppage will result, because the 
feed rib goes back and gets a new cartridge and jams it 
against the head of the one which was left in the chamber. 

Second Position. 

107. Failure to fire. Cause, obstruction lodging between 
face of bolt and the breech, thus holding firing pin away from 
primer. Primer will be slightly dented. This stoppage is 
typical. When the piece stops in the second position always 
look for an obstruction either on the face of the bolt or in 
breech recess where bolt and receiver join. Most frequent 
obstruction is the blown primer. Often it is difficult to see. 


Frequently it drops off as the bolt is drawn back. If the 
stoppage recurs you may be sure that an obstruction is in the 
rifle between the face of the bolt and the breech or between 
bolt lock and receiver top-plate. 

108. Mechanism wedged fast in second position or begin- 
ning of third position. This is a rare stoppage. Slide can- 
not be moved forward or back. This stoppage happens when 
any obstruction gets between one of the bolt supports and 
the bolt lock during the beginning of the first phase. As 
the slide is driven to the rear by the force of the explosion 
the bolt lock is wedged by the obstruction. This stoppage 
has been caused by blown primers and by a piece of metal 
broken off from the rear slotted end of the firing pin chan- 
nel wall. To reduce it, (a) remove trigger mechanism, gas 
cylinder and recoil spring; (b) tap on. rear end of slide with 
piece of wood or a pewter hammer until bolt lock locks. Re- 
move obstruction. Do not hammer with steel or iron. 

Third Position. 

109. Cartridge jam. Due (a) to deformed cartridge; (b) 
to loaded cartridge being held out of chamber by empty 
case which was not extracted; (c) to failure to eject prop- 
erly, empty case remaining in the ejection opening. 

Such failure to properly eject is caused by insufficient gas 
or by failure of extractor to hold cartridge in such position 
that it will be properly struck by the ejector. Weak extrac- 
tor spring or burred shoulder of extractor or extraneous mat- 
ter in seat of shoulder of extractor are the causes of the 
failure of the extractor to properly hold cartridges for the 

This same stoppage will occur when there is insufficient 
gas to drive the bolt baclt with enough force so that the 
ejector may be struck with sufficient force by the cartridge 
to cause ejection. 

Fourth Position. 

110. One fourth position stoppage, developed so far, has 
been in the case of blown primers wedging themselves be- 
tween the point of the ejector and the face of the bolt, thereby 
holding the bolt and mechanism back in the fourth position. 

111. Another fourth position stoppage is where the piece 
is cocked and the trigger mechanism will not release the sear 
when set at (A) or (F). This is due to a broken sear spring, 


a broken or lost connector, an improper assembling of the 
sear spring, or to any cause which has the effect of moving 
the middle prong of the sear spring too far to the front, with 
respect to the connector, so that the connector is not cammed 
under tail of sear. 


112. Introduction. The instructor will impress on the men 
the vital necessity for cleaning and caring for the weapon. 

113. Explanation-demonstration. He will explain and 
demonstrate the care and preservation of the bore, as set 
forth in the Small Arms Firing Manual (care must be taken 
not to allow any of these solutions to remain in the rifle, par- 
ticularly in the gas system). The test given below on points 
to be observed before, during and after firing, will be ex- 
plained and demonstrated by the instructor and imitated by 
the students; the latter will be required to memorize same. 
They will be questioned as in previous lessons. 

114. Whenever the pieces are cleaned they will be thor- 
oughly inspected before being assembled. 

Points to Be Observed. 

115. Before firing: 

(1) Test trigger mechanism at safe (A) and (F). 

(2) See that bore is clear and clean. 

(3) Work slide back and forth rapidly several times to see 
that it moves free!, and does not stick. 

(4) Test ejector and extractor with dummy or empty case. 

(5) Verify proper setting of gas port. 

(6) Verify oiling. 

(7) Verify cleaning. 

(8) Examine magazines and eliminate faulty ones. 

(9) See that kit contains oil can full of oil and full com- 
plement of spare parts. 

116. During firing: 

(1) Keep magazines and chamber protected from dirt. 

(2) Do not allow rifle to become dry. 

(3) Clean bore and gas system frequently. 

117. After firing: 

(1) Remove loaded magazine and replace with empty. 

(2) Let bolt forward. 

(3) Wipe out bore and oil rifle. 

(4) Thoroughly clean rifle at first opportunity. 




118. The Browning automatic rifle team consists of a gun- 
ner, who is team commander, and two carriers (a loader and 
a scout). 

A squad consists of two teams under a corporal. 
A section consists of two squads under a sergeant who is 
section leader. 

Outline of Training of Automatic Rifle Section. 
(Read paragraphs 1-6 I. D. R.). 

119. The training of the automatic rifle section is divided 
into four phases: 

(1) Instruction of the individual. 

(2) Training of the rifle team. 

(3) Training of the squad. 

(4) Training of the section. 

120. All members of the rifle squad should be strong, husky 
men on account of the very heavy equipment of the automatic 
rifleman. They should be intelligent men and expert shots, 
otherwise full advantage will not be taken of the great power 
of this weapon. 

Who Receives It. 

121. All members or tne automatic rifle section should re- 
ceive such instruction that any one of them will be able to 
act as gunner and to keep the piece in action should the 
others be disabled. 

Scope of Instruction. 

122. The instruction of the individual should cover: 

(1) A thorough knowledge of mechanism, stoppages and 
immediate action. 

(2) Firing positions. 

(3) Marching fire. 


(4) Use of sling. 

(5) Loading. 

(6) Marksmanship (prescribed elsewhere). 

(7) Filling magazines. 

(8) Target designation and preparation of range cards 
(prescribed elsewhere). 

(9) Ability to recognize and choose the best positions for 
the automatic rifle (prescribed elsewhere). 

(10) Such technique and theory of fire as applies to the 
automatic rifle. This includes auxiliary aiming, use of night 
firing box, etc. (prescribed elsewhere). 

Firing Positions. 

From the Shoulder. 

123. When fired from the shoulder the position with the 
Browning automatic rifle, prone*, sitting, kneeling and stand- 
ing, is a modification of that used with the service magazine 

124. When firing with automatic setting (exceptional) the 
soldier will lean into the piece as he would lean into a strong 
wind. The effect of the recoil is that of a strong, steady 
push against the firer. 

Adjustment of Sling for Marching Fire. 

125. The gunner having previously adjusted the sling, as 
to length, grasps same at the middle with his left hand and 
allows the rifle to hang by the sling with the barrel down, 
raises rifle with left hand and slips sling over the head and 
on to the left shoulder, at the same time passing right hand 
through the sling and grasping receiver at ejection opening. 
He then turns rifle counter-clockwise and with the right 
hand passes rear end of sling to rear and under butt so that 
it extends from rear sling swivel, along right side of stock, 
behind the back and over the left shoulder, thence to front 
sling swivel. The gunner having adjusted the sling inserts 
the butt in the butt support. (See Plate II). 

126. The sling should be of such length as to hold the 
rifle barrel horizontal when the rifle is not supported by the 
gunners' hand. 

127. For close order the sling should be of such length as 
to allow the rifle to be carried behind the right shoulder, 
with the sling passing over the right shoulder only. For ex- 


tended order, the rifle is always slung as for Marching Fire. 
The rifle should be so slung at any preparatory command for 

128. During the execution of the Manual, the rifle is kept 
at the order arms. 

Marching Fire. 
(See Plate III.) 

129. The following position is prescribed for firing while 
marching. The sling adjusted as described above (paragraph 
125), left hand grasps forearm, thumb extended along fore- 
arm, sling pulled taut. Right hand just in front of comb of 
stock with fore-finger in trigger guard. The rifle being firmly 
supported by the butt support and the sling, directed with the 
left hand and fired with the right. 

130. The above described position should always be used 
in marching fire when the gunner is provided with a butt 
support. It has been found, when the butt support is lost 
or not available, that the gun may be fired while marching by 
placing the butt of the rifle in the pit of the stomach and sup- 
porting the rifle with the sling in a similar manner to that 
described above. The firer should bend over well at the 
waist and bend his knees slightly while firing. 

131. Firing with the butt of the rifle in the pit of the 
stomach is an uncomfortable position for some men. The 
rifle may be fired by adjusting the sling as before, except 
that it is shortened so as to support the forward end of the 
rifle when the butt is held under the arm pit. The butt is 
raised well up under the arm pit and the stock clamped 
with the right arm. The rifle is pushed forward against the 
sling until the latter gives it a steady support. 

132. Any position but that prescribed in paragraph 129 
(from the hip, using butt support), is to be regarded as excep- 
tional and should not be used except when the gunner has no 
butt support. 

133. After the soldier has been thoroughly instructed in 
the position, while at the halt, he will simulate fire while 
marching (commands and signals for firing, those prescribed 
in I. D. R., except as noted hereafter). The gunner advances, 
firing as either foot strikes the ground and between steps. 
He keeps his eyes on the target and corrects elevation by 
observation f impact. 


The sling adjusted for marching fire. 


Position for firing from hip, using butt support. 


Scope of Training. 

134. The rifle team should be so trained as to get maximum 
efficiency out of the efforts of the individual members. This 
requires co-ordination of all their activities. The training 
should include the following: 

(1) Drill. Taking up different formations and the duties 
of the gunner and ammunition carriers. 

(2) Maneuvering through the various formations of close 
order drill suitable for use with the automatic rifle team and 
the thorough training of the gunner and carriers in their 
duties in each of the several formations. 

(3) Utilization of natural features as regards cover. 

(4) Service of the piece by two members of the team and 
by one man alone. Exchange of magazines by first and second 
carriers and loading of magazines while in position. 

(5) Advance of the team as a whole. 

(6) Advance of the team moving forward one man at a 

(7) Transmitting of fire orders from a corporal or ser- 
geant to the gunner by the first carrier. 

Formation of the Team. 

135. For drill, the team is formed in single rank. The team 
acting alone maneuvers on the gunner as the base. Post of 
the first carrier is by the gunner's side and on his right. 
When the team is deployed, the first carrier (loader), .at any 
command or signal for firing, places his left hand on the gun- 
ner's shoulder for the purpose of preserving alignment and 
interval and transmitting signals. The second carrier (scout) 
posts himself on a flank five paces to the right or left of the 

136. In action the scout should be on the most exposed 
flank as a rule. For the purpose of drill-, scouts of front rank 
teams post themselves on the right of the gunner and scouts 
of rear rank teams on the left of the gunner. 


Duties of the Members of the Rifle Team. 

137. Gunner: 

(1) To direct his fire on the target. 

(2) To assist the loader in loading. 

(3) To load when firing alone. 

(4) To reduce stoppages. 

(5) To hold his own ammunition as a reserve. 

(6) To clean with loader's assistance. 

138. First Carrier (loader): 

(1) To watch for signals and transmit same to the gunner. 

(2) To watch for stoppages and assist in reducing same. 

(3) To call magazine when the one in use is empty. 

(4) To load. 

(5) To change empty magazines for full ones. This ex- 
change is made by bandolier or a belt with the scout, cor- 
poral and sergeant successively. 

(6) To preserve alignment and interval for gunner. 

(7) To assist in cleaning rifle. 

139. Second Carrier (scout) : 

(1) To exchange magazines with loader. 

(2) To fill empty magazines. 

(3) To spot shots for gunner. 

(4) To act as scout and protect the team when the rifle is 
out of action. 

To Load. 

140. Command. 1. MAGAZINE. At this command the 
gunner inclines the barrel to the left and releases the maga- 
zine catch. He then cocks the piece. 

The loader habitually marches, when deployed, with a 
loaded magazine in his right hand, base in palm of hand, 
thumb pointing in same direction as cartridges. At the com- 
mand MAGAZINE, he withdraws empty with left hand and, 
holding it with last two fingers in the palm of the hand, 
grasps trigger mechanism between thumb and first two fin 
gers, fingers on left hand side (see Plate IV). Thumb and 
fingers extend slight distance in front of trigger mechanism 
so as to assist in guiding the magazine. He inserts and 
pushes home the loaded magazine with right hand. He then 
returns empty magazine to pocket and draws out a loaded 
one which he carries as described above. 


Magazines are carried in pockets with cartridges down and 
bullets in one pointing in opposite direction to those in other. 

Loading Exercise. 

141. The following drill should be given to perfect the team 
in loading, the piece being loaded and cocked, empty maga- 
zines being used throughout. 

Command. 1. Magazine, 2. FIRE. At (1) the piece is 
loaded as prescribed above. At (2) the gunner aims and 
fires. These commands are repeated as long as the instructor 

Position of loader's fingers on trigger guard, when loading. 

142. Being deployed, to commence firing: 

(1) Range, 300. 

(2) Target, enemy patrol at one o'clock. 

(3) Rate (so many) shots per minute. 

(4) Commence firing. 

(5) Cease firing, or suspend firing. 


i-J-3. At the first command the team assumes the prone 
firing position, as already explained, and the gunner sets the 
sights. At the second command the gunner lays on the tar- 
get. At the fourth command the gunner begins firing semi- 
automatically, at rate prescribed, unless a different class of 
fire has been indicated. During the firing the team performs 
the duties explained above. At the command cease firing > 
the rifle is set at safe. Sight leaf is laid down. In other 
respects the team maintains the prone position. At the 
command suspend firing fire is stopped. Pieces are held 
loaded and locked in a position of readiness for an instant 
resumption of firing. 

To Lie Down. 

144. LIE DOWN: 

(1) Gunner assumes the prone firing position, as pre- 
scribed in the Infantry Drill Regulations. Adjusts the sling 
if necessary. 

(2) Loader (first carrier) jumps immediately to the side 
of the gunner and drops to the ground ready to perform his 
function in firing. 

(3) The scout (second carrier) closes at once to five yards 
from the gun and drops to the prone position on the ground. 

Marching Fire. 

145. The piece is habitually loaded when the team is de- 

Command.!, Marching Fire, 2, COMMENCE FIRING, 

At (1) the gunner brings his piece to the marching fire 
position and cocks it. The loader places his hand on the 
gunner's right shoulder. At (2) the team takes up the 
march (if at the halt) and commences firing, semi-automatic 

Field Cleaning. 

146. When necessary to clean the rifle in the field or a 
shell hole the gunner and loader clean the piece. 

Command. 1, Clean 2, RIFLE. At (2) gunner throws out 
the cleaning kit and starts stripping the rifle. The first car- 
rier opens kit, strips, cleans and reassembles the gas cylinder 
tube, gas cylinder, etc. The gunner continues stripping the 


piece and cleans the barrel (loader should have finished 
cleaning the gas cylinder assembly by the time the gunner 
finishes the bore). Loader then cleans the bolt, bolt lock 
and hammer and starts on the piston and slide. The gun- 
ner thoroughly cleans receiver and reassembles bolt mechan- 
ism and slide. While the gunner completes assembling the 
piece the first carrier oils trigger mechanism and packs up 
cleaning kit. 

The scout refills empty magazines. 


147. The squad is formed in close order as prescribed in 
Infantry Drill Regulations, with a team in each rank. The 
front rank team is known as team A and the one in the rear 
rank as team B. 

The posts then in close order are as follows: 

Front Rank. No. 1, scout (second carrier), No. 2, loader 

(first carrier), No. 3, gunner, No. 4 corporal. 
Rear Rank. No. 1, loader (first carrier), No. 2, gunner, 

No. 3, blank file, No. 4, scout (second carrier). 


148. The squad drills in close and extended order as pre- 
scribed in the I. D. R., except as herein stated. 

Duties of the Corporal. 

149. (1) To watch for signals from section or platoon 
leader and repeat same back. 

(2) To assign rifle positions, sectors of fire and to desig- 
nate targets. 

(3) To exercise general supervision over rifle teams. 


150. Being in line, to deploy. 1. As Skirmishers, 2. 

At (1) the corporal places himself in front of his squad, if 
not already there. At (2) team A, moving at a run, deploys 
abreast of and on the right of the corporal, with five-pace 
interval between skirmishers. Team B, moving at a run, de- 


ploys abreast of and on the left of the corporal, with five 
paces interval between skirmishers. 

This deployment places the corporal between his teams, a 
scout on both flanks and each loader on the right of his 
gunner. It must be remembered that the posts of the cor- 
poral and scout are fixed only for purposes of drill. 

151. Being deployed, to advance by rushes: 
Command.!. BY TEAM (ONE MAN) RUSH. 

The squad leader gives the signal ADVANCE BY 
RUSHES, as prescribed in the I. D. R. and, in addition, 
holds up one finger if the advance is to be made one man at 
a time and three fingers spread if it is to be by team. If the 
advance is by team, the whole team rushes forward at once, 
maintaining their normal intervals. If the rush is by one 
man, the scout is the first to go forward. He advances to 
the position he wishes to occupy, taking advantage of all 
cover afforded by the terrain or by intervening shell holes. 
In general, this advance should not be more than fifty yards. 
With his intrenching tool he prepares a position for the gun 
and then signals to the gunner "ready." The gunner then 
advances in the same manner and opens fire as soon as his 
gun is in position, the scout serving the rifle until the loader 
arrives. The loader, after picking up all magazines, ad- 
vances. If the advance is made from a trench or a shell 
hole each man should leave from a different point, as a sniper 
might train his sights upon any fixed point of departure, 
shooting each member as he appears, successively. 

152. Being in skirmish line: 
Command. 1. Squad columns, 2. MARCH. 

Each squad leader moves to the front, followed in suc- 
cession by the front and rear ranks in single file. 

Continuous Fire. 

153. Command. 1. Continuous fire, 2. COMMENCE FIR- 

At (2) the A team gunner opens fire. Just before his. maga- 
zine is exhausted the A team loader signals COMMENCE 
FIRING to the B team; the rifles thus alternate fire. 

They will habitually fire with semi-automatic setting. 



154. When firing from shell holes no fixed regulations can 
be prescribed. The members of the team conform to the 
principles laid down above. 

155. When advancing by rushes, by team, the advance of 
one rifle is covered by the fire of the other. 


156. The section executes the movements and firings as 
explained for the team and squad. The section leader nor- 
mally takes post in rear of the center of his section but he 
may go wherever his presence is needed. 

157. Except in marching fire the section will seldom act as 
a unit, but rather as two squads whose action will be super- 
vised by the sergeant of the section. The duties of the ser- 
geant will thus usually be those pertaining to fire direction 
rather than fire control. The sergeant, under the orders of 
the platoon leader, will be responsible for the training of 
the section. 

158. Being in skirmish line: 
Command. 1. Section column, 2. MARCH. 

The section leader moves forward through the center of 
the section. The squad to the right of the section leader 
marches to the left and follows him in file; the squad to the 
left marches in like manner to the right. Each section 
leader then conducts the march of his section in double 
column of files. 

159. Being in skirmish line: 

Command. 1. Section column of files. 2. MARCH. 

The section leader moves forward through the center of 
the section; the squad to the right of the section leader 
marches to the left and follows him in file; the squad to 
the left marches to the right and follows the right squad 
in file. 

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