ACP means Automatic Colt Pistol. .45 ACP and .45 Auto are the same cartridge. .45 Colt and .45 Auto Rim are a revolver cartridge. .45 GAP (Glock Auto Pistol) is a shorter round than the ACP, and does not interchange with it.
.45 ACP means Automatic Colt Pistol. It IS .45 Auto.
Automatic Colt Pistol. Colt invented the .45 Auto and thus had the right to name it.
Different names for the same cartridge.
Anniston Army Depot
1918
You will have to call Colt to find out.
The Colt M1911 and the colt M1911A has only 1 caliber .45 or 45/100 of an inch. This round is also known as the colt .45 A.C.P. (all Colt pistols) It is a short round which differs from the .45 long round.
Caliber refers to the diameter of a bullet. A bullet for a .38 Special is actually .357 inches across, and for a .45 auto, about .451 inches. The 45 bullet will be wider, and usually heavier. Please note that this is only the BULLET, which is the projectile. The CARTRIDGE (case, primer, powder, bullet) of the two are different size, shape, design and weight. There also is the .45 Colt bullet (often referred to as a .45 Long Colt). This is about the same diameter as the .45 auto but has a longer cartridge than the .45 auto or 38 Special.
100-10000 USD
100-800
There are currently no semi auto firearms on the market which chamber the .45 Long Colt.