firearms; component parts for firearms; firearm accessories, namely, barrels, upper receivers, lower receivers, actions, bolts, frames, flash hiders, flash suppressors, fake suppressors, triggers, trigger groups, trigger systems, hammers, firing pins, shrouds, lugs, magazines, gas blocks, gas systems, gas tubes, pistons, stocks, adjustable stocks, grips, hand guards, springs, recoil springs, butt plates, housings, mounts, scope mounts, rails, rail systems, accessory mounts, tubes, lanyards, s...