Handgun cartridge naming is an aspect of firearm ownership that can be confusing to new shooters at first – and if you decide to get yourself a full-size Sig Sauer 1911 or Glock 21, you might note on the barrel that it says, “45 Auto.” Excited to get some ammo for your new sidearm, you peruse the gun store shelves and are dismayed to only find boxes labeled, “45 ACP.”
This leads many new shooters to wonder, “Is 45 Auto the same as 45 ACP?”
Although they have different names, the 45 Auto and 45 ACP cartridge are the same.
So why is 45 Auto and 45 ACP labeled differently? We’ll get to that! In this article we’ll explain the differences in cartridge naming for the 45 ACP/45 Auto as well as explore some different varieties of 45 caliber handgun rounds.
Read 45 ACP vs 45 Auto: Are They the Same or Different? at Ammo.com.