Abstract: An accessorized firearm can include a firearm including a barrel having a main firing tube, the barrel provided with an alignment key; and a muzzle accessory including an accessory body having a through-channel and a surface provided with an alignment groove, the through-channel receiving the barrel of the firearm, the alignment groove receiving the alignment key, the alignment key rotationally fixing the muzzle accessory relative to the barrel.

Abstract: A muzzle accessory for installation on a barrel of a firearm is provided. The muzzle accessory includes an accessory body having a through-channel sized to receive the barrel of the firearm; and a locking member structured to engage the groove of the barrel to lock the muzzle accessory to the barrel.

Abstract: A muzzle accessory for installation on a barrel of a firearm is provided. The muzzle accessory includes an accessory body having a through-channel sized to receive the barrel of the firearm; and a locking member structured to engage the groove of the barrel to lock the muzzle accessory to the barrel.

Abstract: A magazine extension is provided. The magazine extension includes a baseplate structured to receive a lower open end of a magazine, the baseplate having a laterally extending through-bore; a side bracket structured to couple to the baseplate for securing the magazine, the side bracket having a laterally extending through-bore; and a locking pin insertable within both the through-bore of the baseplate and the through-bore of the side bracket to lock the side bracket to the baseplate.

Abstract: A magazine extender is provided. The magazine extender includes a baseplate structured to receive a lower open end of a magazine; a side bracket structured to couple to the baseplate for securing the magazine; and a locking pin selectively moveable into a locked position to lock the side bracket to the baseplate and an unlocked position to unlock the side bracket from the baseplate. The locking pin of the magazine extender is prevented from being moved to the unlocked position by a handgrip of a firearm when the magazine is inserted into the handgrip.