13 Firearm parts and accessories, namely, non-telescopic front and rear sights, non-telescopic backup iron sights, magazines and ammunition feeding devices, upper and lower receiver assemblies, trigger group assemblies, bolts and bolt carrier groups, stock parts, foregrips, vertical grips, pistol grips, buffer tubes, handguards, accessory rails, threaded barrel adapters, muzzle devices, recoil reducers, selector switches, manual safety switches, slides, recoil guide rods; gas systems, namely gas-operated recoil systems comprised of recoil pads, recoil guide rods