The cartridge formerly designated "45 ACP" was obsoleted prior to World War II and reintroduced with the designation "45 Auto". Where have you and others on this thread been?
Look at the ammunition. To paraphrase James Carville, "Its the headstamp stupid.
The use of an obsoleted cartridge designation is no more appropriate than addressing a married woman by her maiden name.
And please don't waste time listing examples of other folks that don't know better. A 1,000 wrongs don't make a right. All responsible gun and ammunition manufactures use the correct nomenclature on their firearms and ammunition headstamps.
Yes, Springfield Armory, Kimber and many off-shore outfits can be counted amount the irresponsible.
I don’t know what you are talking about, I put 45 ACP +p bullets in my clip all the time.
; )