Abstract: An apparatus includes a bolt carrier assembly and a bolt assembly. The bolt assembly includes a bolt body member, the bolt body member having a proximal end portion and a distal end portion, and defining a longitudinal axis extending from the proximal end to the distal end. The bolt assembly includes a guide member attached to proximal end portion and the guide member is parallel to the longitudinal axis. The bolt assembly further includes a bolt chamber interface attached to a distal end portion, the bolt chamber interface nests within an interior wall of a firearm chamber, and the bolt chamber interface limits rotational and axial movement of the bolt assembly relative to the firearm chamber. The bolt assembly includes a bolt nipple connector for mating with a nipple assembly of a magazine assembly.

Abstract: An apparatus includes a bolt carrier assembly and a bolt assembly. The bolt assembly includes a bolt body member, the bolt body member having a proximal end portion and a distal end portion, and defining a longitudinal axis extending from the proximal end to the distal end. The bolt assembly includes a guide member attached to proximal end portion and the guide member is parallel to the longitudinal axis. The bolt assembly further includes a bolt chamber interface attached to a distal end portion, the bolt chamber interface nests within an interior wall of a firearm chamber, and the bolt chamber interface limits rotational and axial movement of the bolt assembly relative to the firearm chamber. The bolt assembly includes a bolt nipple connector for mating with a nipple assembly of a magazine assembly.

Abstract: An apparatus includes a bolt carrier assembly and a bolt assembly. The bolt assembly includes a bolt body member, the bolt body member having a proximal end portion and a distal end portion, and defining a longitudinal axis extending from the proximal end to the distal end. The bolt assembly includes a guide member attached to proximal end portion and the guide member is parallel to the longitudinal axis. The bolt assembly further includes a bolt chamber interface attached to a distal end portion, the bolt chamber interface nests within an interior wall of a firearm chamber, and the bolt chamber interface limits rotational and axial movement of the bolt assembly relative to the firearm chamber. The bolt assembly includes a bolt nipple connector for mating with a nipple assembly of a magazine assembly.

Abstract: An apparatus includes a barrel nut having an inner portion and an outer portion. The inner portion includes a threaded portion and a shoulder. The shoulder is configured to engage a shoulder of a barrel to retain the barrel within a receiver when the threaded portion is coupled to a corresponding threaded portion of the receiver. The outer portion defines an outer diameter such that a gas port of the receiver is exposed independent of a rotational position of the barrel nut relative to the receiver. The outer portion includes an engagement surface and a lock surface. The engagement surface is configured to engage a mounting surface of a handguard. The lock surface defines a frusto-conical shape configured to contact a set screw threadedly engaged with the handguard such that rotational movement of the set screw moves the handguard axially relative to the barrel nut.