Machine pistol with retarded blowback

In a machine pistol having a receiver defining an open breech, means associated with said receiver for gripping the pistol for firing, a barrel having a rearward end connected to said receiver and defining a firing chamber that extends into said receiver and means for feeding ammunition rounds seriatim to said breech, the improvement which comprises:

• a blowback-operable slide assembly adapted for reciprocating movement relative to said receiver and barrel between a forward firing position and a rearward retracted position for transferring an ammunition round from said breech to said firing chamber and for ejecting a spent ammunition cartridge from said breech, said slide assembly including
• a bolt with a leg portion extending forwardly therefrom,
• a tubular cylindrical muzzle sleeve located coaxially on said barrel for sliding movement thereon, said leg portion of said bolt being coextensive with and adjacent said muzzle sleeve and
• disengageable coupling means connecting said bolt and muzzle sleeve to one another,
• said coupling means including first interlocking means formed on said leg portion and second interlocking means formed on the exterior surface of said muzzle sleeve whereby said muzzle sleeve may be rotated on said barrel relative to said leg portion between a released position and a locking position wherein said first and second interlocking means are engaged to prevent axial movement of said muzzle sleeve relative to said leg portion,
• said bolt having a main body located in said breech with a firing pin carried thereby in axial alignment with said barrel, said muzzle sleeve projecting forwardly of the front end of said barrel when said slide assembly is in its forward firing position.

In a machine pistol having a receiver defining an open breech, means associated with said receiver for gripping the pistol for firing, a barrel having a rearward end connected to said receiver and defining a firing chamber that extends into said receiver, means for feeding ammunition rounds seriatim to said breech, a blowback-operable slide assembly adapted for reciprocating movement relative to said receiver and barrel between a forward firing position and a rearward retracted position for transfering an ammunition round from said breech to said firing chamber and for ejecting a spent ammunition cartridge from said breech, resilient means urging said slide assembly to said forward firing position, releasable means for retaining said slide assembly in said rearward retracted position and trigger means for releasing said retaining means, the improvement wherein said slide assembly comprises:

• a bolt block slidable in said breech and having a main body with a firing pin carried thereby in axial alignment with said barrel, and a forwardly extending arm;
• and
• a tubular cylindrical muzzle sleeve operatively connected to said bolt block and coaxially located on said barrel for axial movement thereon between a rearward position and a forward position projecting forwardly from the forward end of said barrel, said muzzle sleeve being connected to said forwardly extending arm by means including at least one rib extending radially from the outer surface of said muzzle sleeve, and cooperating groove means on said arm whereby said muzzle sleeve may be rotated relative to said arm to bring said rib and groove into locking engagement, and means operatively associated with said arm and said muzzle sleeve at the forward ends thereof for locking said barrel against rotation relative to said arm, said muzzle sleeve having a forward end portion with internal means defining at least one rearwardly facing surface, said forward end portion and said rearwardly facing surface being located forwardly of said barrel when said muzzle sleeve is in its forward firing position and a part thereof including said rearwardly facing surface being located forwardly of said barrel when said muzzle sleeve is in its retracted position whereby the momentum of the gases escaping from the forward end of said barrel following firing exerts a force against said rearwardly facing surface to retard rearward movement of said slide assembly.