XM-30 MACHINE PISTOL
CAPACITY 15-OR 30-RQUND
SYSTEM OF OPERATION:
The XM-30 machine pistol operates on the hesitation blow-back principle using a bolt-retarding mechanism to slow down its breech opening. The retarder is necessary since the gun utilizes a more powerful cartridge than the pistol-type ammunition commonly employed in most submachine guns and automatic pistols.
When utilizing low-powered ammunition such as 45 ACP, 9mm, .380, etc. in this system or configuration, the retarder is not necessary since pistol-type ammunition will function safely on the blowback principle using a heavy bolt.
The basic configuration of the XM-30 is advantageous. The grip is placed exactly at its center of gravity and the butt plate line has a dual position index. The upper index position places the bore axis of the barrel well below it, completely eliminating muzzle climb in a full automatic. The butt plate can also be indexed to a lower-than-normal position if the shooter so desires.
The trigger mechanism has been kept to utmost simplicity: the sear doubles as the trigger and is operated by the thumb of the hand grasping the front portion of the receiver in a normal manner while the other hand grasps the grip which contains the magazine.
Both the 30-round and the 15-round clip of Ml carbines can be utilized. The side lug on the left side of the 30-round clip must be filed off so the magazine can be inserted freely into the magazine housing.
The weapon does not have a sight. Since it is designed as a spray-type weapon for close quarters, a sight is not necessary. However, a high-type sight similar to that used on the M16 rifle is adaptable.
Most of the components required to build this weapon are from the Ml carbine itself and are readily available from mailorder suppliers.
NOTE ON COCKING THE WEAPON BEFORE FIRING:
To cock the bolt, insert your finger at the front end of the ejection port. Pull the front shoulder of the bolt carrier to the rear until the sear engages with it, and hold the bolt assembly on the open position ready to fire. If the weapon is not to be fired, apply the safety to prevent the sear from accidentally releasing the bolt carrier, thus firing the weapon unintentionally.
Some difficulty might be encountered in cocking the weapon due to the retarder hooking with the receiver tubing. Before pulling the bolt to cock it, simply push up the retarder with your finger, not cocking the weapon, while the butt plate is resting against your waist.
pin hole and peen both ends to prevent loosening. Magazine catch screw
Magazine catch—form and file soft spring to flat shape before re hardening
Magazine housing—formed, cut, and shaped from 1/8-inch steel sheet. After final forming and cutting, spot-weld housing to receiver.
M2 carbine 30-rourul clip-file off the side lug mating with the side catch of M2 catch so that magazine may be inserted freely into the housing. The J5-round clip need not be modified.
Barrel-support base screws-two sets-hardened Sear nose
Index balls—two pair-1 ¡8-inck-diameter steel balls Index ball spring-Mi carbine extractor spring adaptable Safety block
Safety block connecting pin Front barrel base support
Sear/trigger pin-pin must be peened on both ends to prevent loosening during assembly Sear stop pin Safety lever
Bolt carrier—machining required
Retarder lever-hardened after cutting and polishing
Retarder spring-cut from Ml carbine recoil spring
Note: Bolt retarder mechanism is not necessary when using pistol-type ammunition such as the 45 ACP, 9mm Parabellum cartridge, .380, etc.
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