The idea that someone would buy something as old, low volume, expensive, and specific without knowing what round it shot just doesn't make sense.
How many 1911 descriptions simply say ".45" instead of ".45 ACP"? Anyone buying a 1911 is going to expect the ACP round, unless you specify a variant in another chambering.
Just like if you're shopping for an early 60s Corvette and see a "283" advertised, you don't complain that it's misleading since GM also made inline 6s about that size. If you're buying an early 60s Corvette, you already know it's a V8.