There was of course the .45 S&W round made for the Schofield revolver which the US Army adapted in limited quantities. After this the US .45 round was shortened to fit either. The original cavalry load for the Colt contained 40grs BP, while the shorter version only contained 28grs. This of course was not Per-Se a "Colt" round so there is technically no "Short Colt". It may also be well however to note that many commercial "Smokeless" powder loads put up in cases marked ".45 Colt" were assembled in cases of the shorter S&W length. Considering how many rounds were made in both short & long versions it was simply a natural outcome to refer to the full length Colt round as the "Long Colt". The .45ACP incidently was designed to give ballistics using a small charge of smokeless virtually identical to the "Short" .45 black powder "Colt" round to be fired from the Browning designed "Colt Automatic Pistol". A whole line of cartridges "Introduced" in Browning designed pistols were given the ACP designation. This did not preclude their use in other firearms, anymore than naming the original .30-30 the .30WCF prevented other co's from adopting it.
