Abstract: A firing mechanism provides a secondary interface between a hammer and a sear of a firearm that will automatically be engaged in case a primary interface between the hammer and the sear fails. In various embodiments, an actuator is employed to facilitate engagement of the primary and secondary interfaces.

Abstract: A firing mechanism provides a secondary interface between a hammer and a sear of a firearm that will automatically be engaged in case a primary interface between the hammer and the sear fails. In various embodiments, an actuator is employed to facilitate engagement of the primary and secondary interfaces.

Abstract: A firearm having a top surface to which an optical sight is to be attached having a first portion and an adjacent second portion stepped down from the first portion. An adaptor plate is received in the second portion, its shape corresponding to the second portion to properly orient the adaptor plate. The bottom of the second portion and the underside of the adaptor plate having features to receive a spring. An optical sight is attached with at least one fastener to the first portion and directly to the slide of the pistol with a part of the optical sight cantilevered over the second portion and on the adaptor plate. The upper surface of the adaptor plate has a topography that corresponds to a complimentary topography on the underside of that portion of the optical sight.

Abstract: A firearm having a top surface to which an optical sight is to be attached having a first portion and an adjacent second portion stepped down from the first portion. An adaptor plate is received in the second portion, its shape corresponding to the second portion to properly orient the adaptor plate. The bottom of the second portion and the underside of the adaptor plate having features to receive a spring. An optical sight is attached with at least one fastener to the first portion and directly to the slide of the pistol with a part of the optical sight cantilevered over the second portion and on the adaptor plate. The upper surface of the adaptor plate has a topography that corresponds to a complimentary topography on the underside of that portion of the optical sight.

Abstract: A tactical combat rifle includes a two-part, bolt carrier. The upper part of the bolt carrier rides on rails formed in an upper receiver while the lower part of the bolt carrier, although attached to the upper part and moving with it, engages no supporting surfaces. A piston, driven by combustion gases from a regulatable gas block assembly, strikes the upper bolt carrier in the center of its mass to propel it rearward. The barrel is threaded to a removable barrel extension and secured to the upper receiver. A non-reciprocating charging handle is located far forward and accessible from either side of the upper receiver so the user does not have to lower the rifle from the shoulder or take eyes off the target. Combustion debris is kept away from the lower receiver and bolt so operation is cleaner and cycling rates of fire steadier.