Abstract: A firing pin block for a firearm of the type having a rotary breech bolt, a reciprocating bolt carrier, complementary locking lugs formed on the bolt and barrel to releasably secure them together, and cam means drivingly connecting the bolt and bolt carrier for opening and closing the bolt. The firing pin block positively prevents discharge of the firearm at any time when the bolt is unlocked. It does not rely on the presence or good condition of any separate parts, but instead coordinates the cam-actuated rotary operation of the locking lugs with relative longitudinal displacements between the bolt and bolt carrier, to cause the latter to block an enlarged abutment formed on the firing pin whenever the bolt is unlocked.

Abstract: A firing pin block for a firearm of the type having a reciprocating bolt assembly including a breech bolt and slide block, a firing pin, and a pivotal locking block. The slide block and locking block have cam means which cooperate to pivot the locking block in and out of locking engagement with a recess in the barrel as the slide block is reciprocated to close and open the bolt. The operation of these cam means is coordinated with relative longitudinal displacements between the bolt and slide block so that, at any time the locking block is not completely locked, the slide block prevents sufficient forward movement of an abutment on the firing pin to cause the firearm to discharge. This firing pin block is effective even though the firing pin spring and retaining pin may be broken, distorted, or missing.

Abstract: A detent system for tubular magazine firearms serving the dual function of retaining the magazine spring within the magazine tube when the cap has been removed while also acting as a detent to keep the magazine cap securely tightened during normal use. A plastic member is provided with full and partial longitudinal slots which cooperate with indents on the magazine tube to facilitate assembly of the detent system within the tube. The slots and detents also cooperate to maintain the plastic member securely spring biased in a position so that serrated teeth along a peripheral end surface will intermesh teeth on the inside periphery of the cap in order to maintain the latter securely fastened to the magazine tube.