Hang onto your boots, There is no such cartridge as the .45 ACP
Calm down and take a breath, I am not messing with you I promise. I expect this article will stir up a bunch of controversy but that is not my intention. I hear so many people refer to the .45 Automatic or .45 Auto as the .45 ACP and that is truly incorrect.
Here is my argument, first of all you see the in the above photo the rollmark on a Colt M1991A1 barrel hood and like all Colts and other handguns chambered in the .45 Auto cartridge the barrel hood is rollmarked as such. ACP stands for Automatic Colt Pistol and is the platform the .45 Auto cartridge is fired from.
Next up, when you go buy a box of cartridges for your .45 Auto pistol, even in you ask for .45 ACP, the box and headstamps are marked .45 Auto.
Next up of the 9th edition of the Hornady manual on page 850 Hornady explains how, though the cartridge is often referred to .45 ACP this is incorrect. I read the exact words in the video.
In the past few years I have heard of firearms and cartridge boxes marked .45 ACP so here I present the indisputable evidence, straight from SAAMI. SAMMI is Sporting Arms and Ammunition Manufacturers’ Institute. From their website ” SAAMI is an association of the nation’s leading manufacturers of firearms, ammunition and components. SAAMI was founded in 1926 at the request of the federal government and tasked with:
- Creating and publishing industry standards for safety, interchangeability, reliability and quality
- Coordinating technical data
- Promoting safe and responsible firearms use
The work at SAAMI is accomplished by its committees. Technical excellence is always our goal and safety is always the prerequisite.”
So SAAMI is the governing body on cartridges, their dimensions, pressure ceilings, and chamber dimensions. As far as who has the final word, it is they.
Search SAAMI for .45 ACP, and no one is home.
Search for .45 Automatic and you have the option to download a few PDFs with detailed information of the .45 Automatic cartridge.
Here is the contents page leading to the info, notice .45 ACP is not listed while .45 Automatic is.
I am not doing publishing this article to upset anyone or rock the boat but solely in the interest in providing correct information. The better we are all educated the better off we all are. I see many people ask if .45 ACP and .45 Automatic is the same cartridge and so with such misinformation, many people go in to their gunstore asking for one thing and get another.
I myself went into a local gunstore and asked for a box of .45 Automatic and they guy behind the counter asked me if I meant .45 ACP, I said not I want .45 Auto and he looked me straight in the eyes and told me “I don’t think you know what you want maybe you should learn about handguns before you get one” This was not that long ago and can you imagine what I wanted to tell this idiot. Fortunately an older gentleman, working there, walked a box of .45 Auto to the counter and sat it down and said “This is what he wants”. The guy said, yea .45 ACP .Do you care to guess how the box and case head was marked because I damned sure showed him the .45 Auto label.
The ACP designation hearkens back to a time when Colt was the only commercial producer of the Government Model .45 Automatic pistol. I’ve seen very old cartridge boxes marked 45 Automatic, Colt Pistol. Read that again. 45 Automatic…comma…Colt Pistol. The comma carries weight. I’ve also seen a few marked Colt .45 Automatic, Rimless Smokeless Cartridges. Sometime in the 30s, Automatic, Colt Pistol was abbreviated as A.C.P. for the sake of brevity, and shortly after it became simply ACP in general conversation…for the same reasons. So, while the technical term for the cartridge itself is .45 Automatic…recently shortened to .45 Auto…the ammunition manufacturers can be blamed for its being incorrectly referred to as ACP. The smaller centerfire cartridges that Colt’s pistols were chambered for were also labeled as .25/32/380 Automatic, Colt Pistol…but for some reason they stuck while their big brother went on to cause inane arguments on the internet. – John Travis
U.M.C. .45 A.C.P. was the cartridge that came before the .45 Automatic but they are not the same. The official designation is ” Cal. .45 Automatic Pistol Ball Cartridge, Model of 1911“.
Please watch the video and lets start a discussion on this topic.
Thanks to SAAMI for the information and keeping us straight.