Abstract: A muzzle brake for a firearm is described. In one example, an apparatus includes an inner shroud, an outer shroud, and an attachment portion. The inner shroud is configured to permit passage of a bullet from a firearm through a longitudinal axis and having a plurality of inner vents configured to vent gases caused by the passage of the bullet. The outer shroud is at least partially disposed around the longitudinal axis of the inner shroud and forms a chamber between the inner shroud and the outer shroud. The outer shroud has a plurality of outer vents configured to further vent the gases received through the plurality of inner vents. The attachment portion is connected to at least one of the inner shroud or the outer shroud. The attachment portion is configured to form a removable attachment to a part of the firearm that is other than a barrel of the firearm.

Abstract: A rail system for a firearm is described. In one example, an apparatus includes a barrel nut and a modular rail. The barrel nut is configured to secure a barrel of a firearm and has a non-circular outer surface when taken along an axis that is perpendicular to an axis of the barrel when secured to the firearm. The modular rail has an inner portion having a shape that is complementary to the barrel nut such that the modular rail does not rotate about the axis of the barrel when the inner portion is mated to the outer surface of the barrel nut. The outer surface of the barrel nut may also comprise a cavity and the modular rail may further comprise a rotatable assembly configured to engage the cavity of the barrel nut such that the modular rail does not move along the axis of the barrel.

Abstract: A magazine insertion guide is described. In one example, the magazine insertion guide includes a securing portion configured to be secured to a pistol grip of a firearm and a guide portion. The guide portion includes ramped internal surfaces configured to guide insertion of a magazine into an interior of the pistol grip of the firearm and a plurality of sides that are configured to at least partially surround the pistol grip of the firearm and has an opening configured to permit installation and removal of a plurality of different sized backstraps when the securing portion is secured to the pistol grip of the firearm and without removal of the securing portion.