Abstract: A semiautomatic firearm with a reciprocating bolt assembly has delayed blowback and a firing pin block. The firearm is particularly suitable for firing necked rimfire cartridges with a high level of reliability. Features prevent out-of-battery firing, when the bolt assembly is not fully engaged to the firing chamber or barrel face, a movable member within a bolt body functions as a blocking member that blocks the firing pin and prevents the firing pin from striking a cartridge. In embodiments, the firing pin has two stop portions that the movable member can engage depending on the cycle status of the firearm. A reverse cam mechanism associated with the firing pin blocking provides a resistance to and delays blowback. The bolt may interface with the necked rimfire cartridge using a undercut engagement on the forward end of the bolt. The semiautomatic firearm also may incorporate one or both of a dual trigger arrangement as part of a trigger and firing mechanism.

Abstract: A semiautomatic firearm with redundant systems for reducing misfirings. A safety trigger is provided that is passively actuated in advance of a firing trigger. The safety trigger maintains redundant safety mechanisms that prevent inadvertent or accidental actuation of the firing trigger. The firing trigger can be configured for actuation with a very low magnitude or “soft” pull without compromising safety. For the disclosed embodiments, the safety trigger assures that the firearm is discharged only upon deliberate actuation of the firing trigger. In one embodiment, a trigger pull adjustment mechanism provides adjustment of the pull of the firing trigger to a desired force required by the operator. The disclosed trigger pull adjustment mechanism reduces the number of components and complexity of the machined parts over conventional trigger pull adjustment mechanisms.

Abstract: An ejector mechanism for a firearm. The ejector mechanism includes a claw-type extractor disposed opposite a ledge portion that includes an inclined face, the inclined facing being oriented to face toward a bolt face to help secure a shell casing to the bolt face during the extraction process. The claw-type extractor and inclined face, while providing positive retention of the shell casing during ejection, also cooperate to enable the shell casing to be dislodged by an ejector.