And you use an off-shore reference for the proper designation of a U.S. cartridge?
The Sporting Arms and Ammunition Manufacturing Institute (SAAMI) and the American National Standards Institute (ANSI) establish the full and abbreviated names of standardized cartridges. The "ACP" designations were obsoleted prior to World War II. Where have you been? And don't blame the gun writers. It has long been known that their only education in the guns and ammo field is by reading other gun writers. The blind leading the blind.
It is no more appropriate to use obsolete cartridge designations than it is to address a married lady by her maiden name. Please brush up on your knowledge before posting about a subject which you obviously have very little factual information.
Unlike yourself, I realize that common usage serves the purpose of communication just fine, and I don't feel any need to nitpick others in an attempt to fluff my own status. I'm sure you go into a tizzy concerning calling removable magazines clips, but I don't. The only possible confusion would with weapons using both (M1 carbine, M1A1, etc.), otherwise it is a difference without functional distinction.
To say “.45 ACP” has absolutely no possibility of being misconstrued and is in fact still used quite widely. Only someone chock full of themselves would insult another person's intelligence for using it. I tend to use it, as it is period to the weapons I own.
The most intelligent people generally don't feel compelled to be terminology Nazis, when no differentiation in meaning exists. You might know more about firearms than I do, but I seriously doubt it. Sadly, we will never know, as you are incredibly unpleasant to talk to.
Hmm, what if Smith and Wesson's website was to blame?
"Model SW1911 TFP SKU #: 108309 Caliber: .45 ACP Capacity: 8+1 Rounds Barrel Length: 5" / 12.7 cm $1,099.00 "
Or the Taurus website? "Home » Pistol » TAURUS 1911 .45 ACP PISTOL IN BLUE/GRAY TAURUS 1911 .45 ACP PISTOL IN BLUE/GRAY"
Then how will you feed that 45 ACP pistol?