1) Firearm 2) Firearm component 3) Luger pistol 4) Piece 5) Self-loader 6) Small-arm 
In armoured warfare, an autoloader or auto-loader is a mechanical aid or replacement for the personnel that load ordnance into crew-served weapons, such as tanks and artillery. The term is generally only applied to larger weapons that would otherwise have a dedicated person or persons loading them. An autoloader, as its name suggests, extracts a s...
[n] - a firearm that reloads itself
self-loader noun a firearm that reloads itself
a firearm with an automatic loading mechanism.