TB 23-7-1

    4   GENERAL.  Operation and functioning will, for convenience, be divided into two main groups of actions: the manual operations necessary to load, fire and unload the weapon, and the mechanical functioning of the mechanisms when acted upon by the force generated by the expanding powder gas when the cartridge is fired.
     5.  TO LOAD THE MAGAZINE. - Insert 15 cartridges into the magazine one at a time. To insert cartridge, hold magazine in the left hand with the curved open end up and to the right. Grasp a cartridge in the right hand between thumb and forefinger with base to the left. Insert base of cartridge in right end of opening in top of magazine and press down with thumb against follower, forcing cartridge below lips of magazine. Then push cartridge to left, beneath lips, until base of cartridge contacts rear of magazine tube. Grasp another cartridge in the same manner and press down upon the first cartridge and slide the second cartridge to the left over the first one. Continue thus until all the 15 cartridges are loaded into the clip. The cartridges will be staggered in the magazine when it is fully loaded, with the top cartridge centered between the lips of the magazine. If the follower does not depress smoothly, push down and release a few times. If this does not improve the action, look for dents, rust or foreign matter in magazine tube, or for bent follower.
     6. TO LOAD THE CARBINE. --  a. Insert a loaded magazine into opening in receiver with the retaining lugs (flat face) to the rear and push it up until the magazine catch snaps into position, below the retaining lugs on the rear face of the magazine tube. If magazine does not snap in easily, depress the catch. Ordinarily this action should be performed with the bolt locked and the hammer let down. This makes it possible to carry the carbine safely with loaded magazine attached, as it cannot be fired until the bolt is retracted and allowed to close and lock.
     b. With loaded magazine latched in position, retract the bolt, with little finger (Figure 4), all the way to rear by pulling back the operating slide handle, and then allow it to snap forward. Unless the bolt is fully retracted, the sear may not be seated properly in the sear notch in the hammer. The carbine is now fully loaded with a cartridge in the chamber and the hammer cocked. To fire the carbine it is now only necessary to pull the trigger and thus release the hammer. When thus loaded, unless the carbine is to be fired immediately, the firing mechanism should be placed at safe by pushing the safety all the way to the right. When thus placed at safe, the safety must be pushed all the way to the left before the trigger can be pulled to fire the weapon (For sight Setting refer to paragraph 2 b (2) (e)).
    7. TO UNLOAD THE CARBINE.-- a. Press the magazine catch to the left and withdraw the magazine from the receiver (Figure 5). Magazine will usually fall out.
     b. Retract the bolt fully by pulling back the operating slide handle. As the bolt moves to the rear it will extract the cartridge seated in the chamber and elect it. The live cartridge case can be prevented from being thrown clear of the receiver by the ejector, and so possibly damaged, by placing the thumb over the receiver, thus blocking the throw of the cartridge. If cartridge is ejected freely, it should be wiped clean of foreign matter before reloading it into the magazine. Examine chamber to see that it is empty before allowing bolt to go forward and close. This is always a safe practice when retracting the bolt, to obviate the possibility of a cartridge being left in the chamber. Ordinarily the bolt should be allowed to close slowly on an empty chamber and not to snap shut.
     c. When it is determined beyond doubt that the chamber is empty and with the magazine removed from the receiver, remove the tension from the hammer spring by pulling the trigger and letting the hammer down. If this is done while the bolt is still partly retracted, the hammer blow on the firing pin will be lessened and the hammer will be let down easily as the bolt closes. The hammer should never be so released when there is a loaded cartridge in the chamber.
     d. To unload the chamber without withdrawing the magazine, retract the bolt, block the extracted cartridge as explained and lift from the receiver. Before allowing the bolt to go forward, depress the top cartridge in the magazine with the thumb so that the bolt will ride over it in closing.  Allow the bolt to close slowly, watching to see that it slides over the top cartridge and closes on an empty chamber. As a rule, however, the magazine should be removed, unless empty, before chamber is unloaded.
    8.  TO OPERATE THE CARBINE AS A SINGLE LOADER.-- With empty magazine in place, retract bolt fully and place a cartridge in the chamber. Allow bolt to close smartly so that extractor will engage base of cartridge and bolt be rotated to full lock. Where noise is a factor, the bolt may be eased to the closed position and the operating slide handle pressed forward at the end of the movement to insure complete locking of the bolt. Unless carbine is to be fired immediately, the firing mechanism should be placed at safe, by pressing safety fully to right. To unload, retract bolt fully to the rear, to eject cartridge, and examine chamber to make sure it is empty, before allowing to close.

     

CAUTION:  During the operation of loading and unloading and placing firing mechanism on safe, the muzzle of the carbine should be pointed down, and care exercised to see that it is not pointing at the foot or anything that could be damaged in case the carbine fires accidentally. Care should always be observed when handling weapons whether loaded or unloaded.
    9.  INDIVIDUAL SAFETY PRECAUTIONS. -- a. Consider every carbine to be loaded until you have examined it and proved it to be unloaded. Never trust your memory as to its condition in this respect.
    b. Never point the carbine at anyone you do not intend to shoot, nor in a direction where an accidental discharge may do harm.
     c. Always fully unload the carbine if it is to be left where someone else may handle it.
      d. Always point the carbine up when snapping the trigger after examination.
     e. If it is desired to carry the carbine cocked, with a cartridge in the chamber, the trigger should be blocked by pushing the safety to the right.
     f. Under no circumstances should the hammer be let down on a partially closed bolt, with a cartridge in the chamber.
     g. Never fire a carbine with any grease, cleaning patch, dust, dirt, mud, snow, or other obstruction in the bore. To do so may burst the barrel or blow the bolt.
     h. Never grease or oil the ammunition. This may affect the ammunition, and creates a hazardous pressure on the carbine bolt. (Refer to paragraph 51).
     i. Chamber and bore should be wiped dry of oil or grease before firing for the reason given in g and h above.
     j. See that ammunition is clean and dry. Examine all live and dummy ammunition. Turn in all cartridges with loose bullets or which appear to be otherwise defective.
     k. Do not allow ammunition to be exposed to the direct rays of the sun for any length of time. This creates hazardous chamber pressure.
    10. REARWARD MOVEMENT OF THE OPERATING MECHANISM. -- In the following description of the mechanical functioning of the carbine, it is assumed that the carbine has lust been fired and that there is a full or partially full magazine in the carbine.
     a. As the bullet passes down the bore, propelled by the force of the expanding powder gas, it passes the gas port in the bore. As the bullet clears the port some of the highly compressed gas, propelling it, passes through the port into the gas cylinder and acts upon the head of the piston. The piston is driven rearward a short distance (about ¼  inch) where it is stopped by contact with the piston nut which locks it in the gas cylinder. The rearward motion of the piston is transferred to the operating slide, the forward face of which has been bearing upon the rear face of the piston. The operating slide is thus driven rearward, carrying with it the bolt with which it is engaged.
     b. Before starting its rearward movement the bolt is rotated slightly through the camming action of the cam aperture in the operating slide (handle) lug with which it is engaged. This cammed rotation disengages the locking lugs of the bolt from the corresponding apertures in the receiver and allows the bolt to be moved to the rear by the operating slide. During this rearward movement the operating slide compresses the operating slide spring which seats in its well in the forward face of the receiver and through its guide bears on the rear face of the operating slide body. The compression of this spring furnishes the power for the forward movement of slide and bolt.
     c. As the bolt moves rearward it withdraws the empty cartridge case from the chamber, gripped in the extractor. As the forward end of the empty case clears the receiver, the ejector (in face of the bolt) which has been held under compression against the base of the cartridge case, throws the case off the bolt and out of the receiver.
     d. While moving to the rear, the rear face of the bolt bears against the forward face of the hammer and thus drives the hammer back and down, rotating it about the hammer pin, until the sear notch of the hammer is in position to be engaged by the nose of the sear. At this point the nose of the sear engages in the sear notch in the hammer and is held in engagement (due to the elongation of the pivot hole) by the pressure of the sear spring, as the bolt rides back over the hammer, for a short distance, to the end of its rearward movement.
    11. FORWARD MOVEMENT OF THE OPERATING MECHANISM.-- When the bolt has reached the limit of its rearward (recoil) movement, it starts forward, propelled by the operating slide. The energy for the forward (counterrecoil) movement of the slide and bolt is furnished by the operating slide spring which was compressed (loaded) during the rearward movement of operating slide. The bolt, moving forward, strikes the base of a cartridge which was centrally positioned in the mouth of the magazine by the magazine follower and spring, after the bolt passed over it during the rearward movement. As the bolt continues forward it pushes the cartridge out of the magazine and into the chamber of the barrel. As the bolt slams shut on the seated cartridge, the extractor is cammed open and its claw then slips into the cannelure in the base of the cartridge. At the same time the ejector, in the face of the bolt, is compressed against its spring by the base of the cartridge. As the bolt moves farther forward, it is rotated by the cam in the operating slide (handle) lug so that, upon closing, its locking lugs are in position in front of the locking shoulders of the receiver. The tang of the firing pin is now in position to mate with the slot in the receiver and be driven forward to fire the cartridge when the hammer is released.
    12. ACTION OF THE TRIGGER MECHANISM. --  a. The recoiil off the bolt is completed so rapidly that the operator has not usually had time to release the trigger. Thus the trigger is still in the rearward position when the hammer is driven back and down (cocked) by the bolt on its rearward (recoil) movement. In this rearward position, the rear end of the trigger is raised and the trigger spring compressed. The sear spring, however, has forced the sear forward, as the (trigger) pin hole in the sear is in the form of an elongated slot. The forward movement of the sear has caused the rear end of the sear to drop below the level of the lip on the rear (top) of the trigger. As the hammer is forced back and down, rotating on its pin by the rearward movement of the bolt, the lower (curved) surface of the hammer rides over the top of the sear until the sear notch in the hammer is in position to be engaged by the sear. At this point the sear spring forces the nose of the sear into engagement with the sear notch in the hammer. The elongated (trigger) pin hole in the sear allows the sear to remain in engagement with the hammer even when the hammer is forced back beyond the cocking' point by the bolt riding over it, in completing the rearward movement.
     b. When the trigger is released, the trigger spring forces its rear end downward, and the hammer spring, acting through the hammer, forces the sear to the rear. This rearward movement of the sear is made possible by the elongated (trigger) pin hole in the sear. The release of the trigger has allowed the lip on its rear (top) end to drop low enough for the sear to ride over, and rest upon it.
     c. If the trigger is now retracted (squeezed), the rear end will rise, carrying with it the rear end of the sear which is now resting upon it. The sear, pivoting about the trigger pin, will have its forward end forced down and thus out of engagement with the sear notch in the hammer. The hammer is thus free to rotate about the hammer pin. It is forced forward by the hammer spring plunger, propelled by the force of the compressed hammer spring, and strikes the tang of the firing pin. The firing pin is thus driven forward to strike the primer which fires the cartridge and starts a new functioning cycle.
     d. In moving forward, the tang of the firing pin must clear a slot in the bridge of the receiver, which can only be done when the bolt is fully rotated to the locked position. If the hammer should strike the firing pin when the bolt is in any other position, the effect would be to deaden the hammer blow and to rotate the bolt towards its locked position.
     e. The carbine is provided with a safety, located in the bow of the trigger housing just forward of the trigger. When it is positioned to the left a slot in the safety permits the forward end of the trigger to be depressed, thus allowing the rear end to rise. If the safety is positioned to the right, the solid part of the safety blocks the forward end of the trigger, and prevents it from being depressed. Thus the rear end cannot rise and the hammer cannot be released.
     f. The magazine is composed of a tube, base, follower and spring. The spring is positioned in the tube between the base and the follower so that when the follower is forced towards the bottom of the tube the spring is compressed. The compression of the spring furnishes the force for feeding the cartridges into position at the mouth of the tube. The cartridges are loaded into the magazine tube one at a time, as described in "To load the magazine," paragraph 5. The magazine is held in position in the bottom of the receiverby the magazine catch as already described.