Both can refer to 45ACP. 45 alone can also refer to 45 Colt
The size of the projectile.
1911 45acp
It is the named of the cartridge it shoots- the .45 Automatic Colt Pistol cartridge.
yes
Mainly in the stock
no, only caps for percussions pistols and caps for percussion rifles. gun stores know the difference.
bronze and gun metal
The Puckle Gun had a bore of 1.25 inches, or 32 millimetres.
Stock dimensions and sights
The M3A1 Grease Gun was a .45ACP, Blowback operated, full automatic submachinegun with 30 rd clips.
You can buy Thompson machine guns on Guns America. They have the Thompson 1927A1 .45ACP for around $1,100.
It has been made in several calibers, but the original was .45 ACP