General Info.

    The U. S. Carbine, Cal..30, M1, commonly known as the M1 carbine, is a gas-operated semi-automatic shoulder weapon with detachable box magazine. Developed by Winchester, it was adopted by the U. S. Service in October 1941, and saw extensive use in both World War II and the Korean War. It was used by many personnel, (officers, non-commissioned officers, administrative personnel, and service troops), and was produced for the Government in huge quantities.
To meet requirements of airborne troops, a modification of the M1 Carbine designated M1A1 was standardized in May 1942. The M1A1 Carbine has a folding metal stock, but its barrel and action assembly is identical to that of the M 1 version.
The M2 and M3 Carbines, standardized in September 1944 and August 1945 respectively, were fitted with a selector switch permitting either semi or full-automatic fire. They were regularly issued with a 30-round capacity box magazine interchangeable with the 15-round magazine. The M2 and M3 Carbines, being capable of full-automatic fire, are classified as "machine guns" under the National Firearms Act. Under the Act, a $200 fee must be paid to the Federal Government before one can legally own, sell, or otherwise transfer a weapon so classified.
During the World War II period there were many modifications and improvements made to parts and accessories for the various models. These included bayonet attachments, grenade
    To load magazine. press cartridge down with thumb until caught under magazine lips. Repeat this procedure until magazine is full. Unload magazine by pushing rounds forward and out one at a time. The 15-round magazine is normally used in the M1 carbine, but the 30-round magazine for the M2 and M3 will also work in the M1

    The carbine is gas-operated, and has a short-stroke piston. As soon as bullet (a) is forward of gas port (b) in barrel, gas from the burning powder expands through gas port into gas cylinder and thrusts the piston (c) rearward. The piston strikes the operating slide (d), starting it into motion, and the piston is stopped after about 3/16" travel by the piston nut. As the operating slide starts to the rear, the operating slide spring {e} begins to be compressed. The operating slide moves about 5/16" before its cam contacts operating lug of bolt. This allows operating slide to gain speed to overcome inertia of the locked bolt, and also gives time for bullet to clear muzzle, allowing pressure in barrel to be reduced to outside pressure before bolt begins to unlock. As operating slide continues to the rear, it compresses the operating slide spring and cams the bolt counterclockwise to unlocked position. Extraction and ejection of fired cartridge case, withdrawal of firing pin to safe position inside bolt. and cocking of hammer occur as bolt moves rearward. When operating slide and bolt move forward, pushed by the compressed operating slide spring. the bolt strips top round from magazine and shoves it 'into chamber. When bolt reaches forward position, cam in operating slide rotates bolt clockwise so that locking lugs on either side of bolt head engage locking shoulders in receiver. The M1 carbine is of semi-automatic type (trigger must be squeezed and then released for each shot)

    Safety (a) of carbine is engaged when rotated so that safety lever points down as shown. To load, engage safety, and insert loaded magazine (b) into magazine opening, making sure magazine snaps into place. With forefinger of right hand hooked over operating slide handle (c), pull operating slide to the rear and release it, closing the bolt. Striking rear of operating slide handle with heel of hand helps to close and lock bolt. To make piece ready for firing, rotate safety to disengaged position (safety lever to rear). To unload, engage safety, depress magazine catch (d) and remove magazine, pull operating slide to the rear and lock it in this position by depressing operating slide stop (e) so that it engages it detent in the receiver. Inspect chamber to make sure carbine is unloaded, and unload magazine. To operate its a single loader, pull operating slide to rear and lock in this position by depressing operating slide stop. Place it round in the chamber, seating it with thumb. Pull operating slide slightly to rear and release it. When operating slide is locked in rear position, avoid hitting butt of carbine on ground or jarring by other means as this is liable to release operating slide, and if cartridge is in chamber or loaded magazine is in carbine, the carbine will be inadvertently made ready to fire. Rear sight is adjustable for elevation by sliding aperture (f) on its ramp. Aperture is adjustable for 100, 200, 250, and 300 yds. Windage is adjusted by turning windage knob (g) One click of windage moves strike of bullet on target approximately) 1" for each 100 yds. of range. The rear sight base has graduations for windage launchers, sights, and design changes in parts including the safety, barrel, hammer, and bolt.

    Prime contractors for production of U. S. cal..30 carbines were: Winchester Repeating Arms Co.; Inland Div., General Motors Corp.; RockOla Corp.; National Postal Meter Co.; International Business Machines Corp.; Underwood Elliott Fisher Co.; Saginaw Steering Gear Div. General Motors Corp.; Standard Products Corp.; Quality Hardware & Machine Corp. In addition there were many subcontractors and parts manufacturers.
    The carbine proved extremely popular with most troops, and many civilian gun enthusiasts have since become intrigued with it. There are several reasons for this popularity, principal ones being that the carbine is light, handy, possesses a sporting rifle balance and appearance, and develops little recoil.

    Service ammunition manufactured for use in U. S. Cal..30 Carbines included a grenade-launching cartridge, tracer cartridges, and a ball cartridge with full jacketed, semi-round-nosed, flat-based bullet with nominal weight of either 108 grs. or 111 grs. depending on presence or absence of hollow cup in the base. The 108-gr. cup-based bullet was manufactured prior to Feb. 14, 1942. Average chamber pressure of the ball cartridge is 40,000 pounds per square inch with nominal muzzle velocity of 1970 feet per second. Corresponding muzzle energy with 108-gr. bullet is 930 foot-pounds, and with 111 gr. bullet is 956 foot-pounds.

Following is the performance of the Cal.30 Carbine Ball Cartridge M1, based on the official firing table:
 
Range)
     (yds)            0     100   200    300
Velocity
    (f.p.s.)       1974   1580   1265   1062
Energy
    (ft.-lbs.)      961    615    394    278
Trajectory
height (in.)         --    1.4    7.0    20.5