Patent attributes
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.