TilE BRO\VNING HEAVY MACHINE GUN ~lec"aDism ~Iade Easy ,300 calibre model I9I7 (WATER COOLED) ALDBRSHOT GALE & POLDEN One Shilling LIMITED and Sixpence (By Post, 1/8) (ne/)
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Contents PAGE GENERAL DESCRIPTION. 5 DATA. 5 FIELD STRIPPING DETAILED HEAD 7 STRIPPING OF GROUPS. SPACE ADJUSTMENT. 9 13 MECHANISM. 16 TRIPOD 21 MOUNTING. SIGHTS 24 FIRING 26 STOPPAGES 29 USEFUL 31 NOTES P,imed in Great Britain by Gale So Polden Ud.
- _a-, 14 IS PLATE I I 2 WaIer jacketWater jacket end cap. 3 4 S Foresight protector. Foresight. Barrel (mu22le end protruding through muzzle gland). Drain plug. Cork plug stem and chain. Steam hose affixed to steam vent. Filler plug. Ammunition box. 6 7 8 9 10 6 II 12 13 14 IS 16 I? 18 Cover. Cover latch. Rearsight. Shock absorber mechanism. Pistol grip. Trigger. R~jver. Trigger pin recess hol.. 19 20 21 Bolt handle. Feedway. Ammunition beit.
~ ~ f~ c~ -~ ~ ~ .Jt.(. . D ,-~~ PLATE (A) (8) (C) 2 Cover group. Shock ab,orber Bolt group. .~ ,- ~ P- Illustrations of Assembled Groups group. (D) (E) (F) - '~-~ Lock frame group. Barrel exten,ion group. Cover latch. FIELD STRIPPING This should be done in the following sequence: (I) Draw back cover latch, raise cover.
(3) Push bolt handle forward a few inches. (4) Push cover latch forward with left hand. Back plate of pistol grip may now be lifted up and out of receiver with right hand. (5) Pull bolt handle to rearmost position and withdraw bolt handle from bolt. (6) Grasp driving spring rod with right hand, withdraw bolt and support same with left hand. Turn extractor upwards and remove. (7) With nose of bullet, push in trigger pin (located in hole on the right side of receiver).
~24 ~~ 30 PLATE 22 23 . -:J8 I 26 " /2B I II ~I 27 "2,9 -= - 31 t) - 3 II Cover. 22 Cover eKtractor earn. 23 Cover eKtractor spring. 24 Belt reed slide. 25 Belt reed pawl. 26 Belt reed paw! pin. Cover Group Siripped 27 28 29 Belt reed pawl spring. Cover pin and spring. Belt reed lever pivot pin and spring. 30 3I Belt reed lever. Belt reed lever actuating stud.
H~ ~-H' ~ 35 '~ ~ - ~, 19-~ 3638 39-<11---. 40 'JJem!J~.I.mJ.Hlm..~ ~ <12 ""- ""lNt/ttmt tltI/ tit IItttlUtffmrmrrrr(ffr~rr\ PLATE 19 32 33 33a 34 3S 36 10 4 Bolt handle. Bolt. Extractor. Ejector. Sear spring and pin. Cocking lever. Cocking lever pin. Bolt Group Stripped 37 38 39 40 41 42 Sear. Striker. Striker spring retaining Striker spring. Driving spring rod. Driving spring. pin.
SHOCK ABSORBER GROUP (Stripping ofthis group is rarely needed except in case ofrepair) (1) Unscrew adjusting screw. (2) Remove adjusting screw plunger and the adjusting screw plunger spring. (3) Remove buffer discs (there are 16 of these), buffer plug, buffer ring and buffer plate. BOLT (1) Remove extractor. (2) With cocking lever in rearmost position insert point of bullet into trigger notch of sear. Press sear downwards, releasing striker. (3) Push out cocking lever pin. (4) Remove cocking lever.
1E"~50' "', 50 4<. - ~-52 ~ ~'~ 5CO> 4). ~ ~-44 5i =-4S 51 "'!'I' ~..... 043 -46 ~ <47 12 - PLATE 6 54 (above) ~ ('LATE Barrel Extension Group SO Barrd cXlension. SOd Lock frame projection grooves. sob T-lug extension. soe Barrel plunger stud. 5I S2 Barrel lock spring. Breech lock. S3 Breech lock pin. PLATE 7 (below) Cover Latch 12 Ower latch. S4 Cover latch .pring. 1Z ~ 5 Lock Frame Group .6 Trigger. 43 43a 43b 43< 44 45 46 47 48 49 Lock frame. Lock frame .pacer.
LOCK FRAME (1) Push out trigger pin and remove trigger pin spring. (2) Remove trigger. (3) Push out accelerator pin, remove accelerator. (4) Push out barrel plunger head pin from slit in left side plate of lock frame. (Take care to keep spring under control whilst doing this.) Barrel plunger and barrel plunger spring may now be withdrawn. BARREL EXTENSION (1) Push out breech lock pin and remove breech lock.
Binding of certain moving parts and slow rate of fire may result. It may not be possible for the mechanism to go fully home to the firing position, when the gun cannot be fired. Breakage of the barrel extension can result from firing the gun with head space too tight. THE CORRECTHEAD SPACE ADJUSTMENT (A) Partly screw barrel into barrel extension. (B) Remove extractor from bolt.
accelerator tips and prevent them proceeding rearwards.) Ensure the lock frame is securely locked to the barrel extension; raise and push forward into the receiver the assembled barrel, barrel extension and lock frame; push in trigger pin, when the whole assembly can be pushed fully forward home, making sure of this by seeing trigger pin res eats itselfin its recess in the right side of receiver. Test that everything is home by pulling on the lock frame spacer rearwards.
1/ ~ - - ~\J1:.. ~ 'r ~ ~='" i: ~ PLATE 8 "~ - 't --Yl8i . / I ~ >0 ~) Sl "3<. . ~ I ~ 4) IlIlemal Medial/ism ill Forward Posiliol/ Bolt (32) forward in firing posiuon. Extractor (33) gripping succeeding round (in belt, not shown). Cocking lever (35) in rcarmost position. Breech lock (52) forced up (by breech lock earn, not shown). Breech lock pin projections (53) clear of lock frame projeCtions (43')' Accelerator claws (44) tipped forward.
33 --n I 50 3S ~.~1 :,c..~d' _. -~~IQFI\' . 'l~\.' / 43<: I ii ~&"7 !lJ ~ '\ 43 -:.. -~PLATE 9 Int.!rnal Mechanism in Backward Position (320) Feed lever actuating stud earn groove. (33) Extractor in position to guide grooved rim of cartridge into T cut of bolt. Barrel extension (5°) stopped from proceeding rearward by lock frame (43). The inclined faces of the lock frame projections (43e) have struck the projections of tbe breeeh lock pin (53), forcing them down and unlocking bolt.
Top ILLUSTRATION:SIww. bol, in fully foro;ard po.irion. Govn raised to $how rllt belt feed arm atruaritlg swd) havillg bun dn"'Uetl to rho lofr whm Io
FEEDI NG OF BELT FEED LEVER BELT STOP PAWL OPERATIONS During the backward movement of the mechanism, the feed lever actuating stud is located in the cam groove in the top of the bolt; thereby its forward end engaged in the belt feed slide is driven to the left. The belt feed pawl is permitted by its spring to ride up and over the next cartridge. The belt is prevented from being carried in the same direction by the belt stop pawl.
The bottom projections of the bolt strike the tips of the accelerator claws, tipping them forward and unlocking the barrel plunger; the barrel plunger spring reasserts itself, driving forward the barrel extension and barrel. The breech lock rides up the breech lock cam to lock bolt to barrel extension and barrel. The sear notches engage the trigger bar. The tip of the cocking lever is returned to its fully backward position.
59 I PLATE 10 Tripod Mounting, 55 Front leg,. 56 Front leg jamming handles. THE TRIPOD 57 58 MOUNTING Trail leg jamming Trnilleg. (MODEL Model 19r8 handles. 1918) The illustration above clearly shows the various parts. To mount gun, turn elevating and trunnion pin handles to . vertical position and withdraw. Place gun on tripod so that its mounting holes coincide with the trunnion bracket holes and elevating bracket holes.
72 69 66 68 67 PLATE II Tripod Head, Model 1918 S9 60 61 62 Front leg dutch plates. Pintle locking handle. Traversing mechanism damp. Slow-motion traversing wheel. 63 64 Slow-motion traversing dial. Slow-motion traversing dial zero adjusunc:nt lock nut. 6S Traversing 6sa Pintle. 22 dial. 66 Elevating 67 Slow-motion wheel. Slow-motion Slow-motion pointer. 68 69 70 71 72 clamp. elevating hand elevation dial. elevation dial Elevating pin. Trunnion pin. Ammunition box braekel.
ELEVATING MECHANISM A slow-motion elevating hand wheel is provided with a mil clicking device. Turned in a forward direction (i.e., forwards away from gunner) raises gun, and turned in the reverse direction lowers gun. Each click represents I mil alteration. Larger alteration in angles of elevation than that provided by the slow-motion elevating hand wheel may be accomplished by loosening elevating clamp and raising or lowering gun.
n 77 7\ 7.. 78 76 , PLATE 12 Bllcksight 73 74 75 Graduated Adjustable Adjustable catch. 76 Fixed open backsight. Adjustable open backsight. 77 lcar. backsight slide. backsight slide 78 79 80 Six-hole adjustable aperture eye-piece. Windage adjustment screw. Elevating screw. fine adjustment SIGHTS FORESIGHT A blade foresight is fitted at the top of end cap of water jacket, being dovetailed into the sight block, and is thereby adjustable laterally.
BACKSIGHT In Plate 12 is illustrated the backsight described in detail below. It is to be noted that guns may be fitted with different types of backsights to the one described. The description that follows should enable other types of backsights to be easily understood and used. It consists of a leaf. In its lowered position an open U backsight is in position, which is sighted for 500 metres. When leaf is raised graduations on the leaf are used by which the slide is set to the range required.
PLATE 13 The BEFORE Firillg Positioll (Grm moull/ed all 1918 Tripod) FIRING PREREQUISITES (I) AmmuniLion loaded into belts. (2) Ammunition boxes. (3) Water condenser filled with water. (4) Combination tool. (5) Cleaning rod. (6) Separated case extractor. (7) Spare parts. NOTE:4, St 6 and 7 aTt essemialfor pemble 'sroppaJfe~. (A) All mechanism must be clean, free from dust, dirt and fluff, and thoroughly oiled.
(c) Muzzle gland should provide a smooth water-tight fit with barrel. The barrel should be well oiled or greased where it slides through muzzle gland. (D) Test head space adjustment. (E) Fill waterjacket. NOTE: Correct carrying out of (B) and (c) should be tested by operating mechanism with bolt handle.
FIRING Set sights to range required. Release elevating and traversing mechanism clamps; align sights on target. See that elevating hand wheel and traversing dial and slowmotion traversing dials are at zero. Tighten elevating and traversing clamps. Check alignment of sights on target by elevating wheel and slow-motion traversing wheel. Insert loaded ammunition belt in feedway, ammunition box having been placed in its bracket on tripod (illustration page 18).
(3) Clean chamber (if dirt, dust or grit particles are present evidence of such will be given by longitudinal scratches o~ ejected cases). (4) Oil mechanism plentifully. (5) Tighten buffer recoil mechanism. STOPPAGES (I) GUN REMEDIED BY IMMEDIATE ACTION FAILS TO FIRE Gunner takes hold of ammunition belt protruding to the right of gun from feedway and gives it a sharp jerk to the right. Cock gun. Relay aim. Continue firing. (2) GUN STILL FAILS TO FIRE Gunner raises cover.
If no round is ejectedInspect chamber. If round in chamberRemove it by passing cleaning rod through barrel from muzzle end and pushing it out of chamber. (Too much force should not be exercised as base of round may be driven forcibly against T cut in bolt, thereby iniuring T cut, or base of round may become jammed in T cut.) If no round is ejected and there is no round in chamberRaise extractor and inspect for round in T cut of bolt.
AFTER FIRING Strip gun. Clean barrel as fer rifle. [Note the hot water in jacket can be used for cleaning bore of barrel as follows: Make a plug with a piece of flannelette round a cartridge case of a size to fit into muzzle gland tightly. Tilt muzzle towards ground. As gunner withdraws barrcI, assistant gunner plugs muzzle gland.
CALIBRATION OF REARSIGHT LEAF Originally the rearsight leaf was calibrated for. 300 '06 ammunition and graduated up to 2,600 yards. Later issues were calibrated for .300 MI ammunition and were graduated up to 3,300 yards. The trajectories of .300 '06 ammunition and .300 MI ammunition differ so slightly up to 800 yards that for practical purposes the sights graduated for '06 ammunition can be used up [0 800 yards when firing M.I ammunition.
