Will the .45 Short or .45 Scholfield fit the Colt .45 with no problems.
Howdy
One of my favorite subjects.
Unlike these other fellows I am going to answer your question with pretty much yes, with an exception.
45 Schofield has always had a larger rim diameter than 45 Colt. That is because 45 Schofield was developed for the S&W Schofield model which used an extractor to pull the empties out of the cylinder by their rims. The rims had to be large enough for an extractor to grab. 45 Colt on the other hand was originally ejected from the SAA by an ejector rod which poked the empties out from the inside. So for 45 Colt rim diameter was not an issue and many early 45 Colt cartridges had very tiny rims, just enough to keep the round from slipping into the chamber.
Fast forward to today and the rim of the 45 Colt is a bit bigger than it used to be, but still smaller than the rim of 45 Schofield. SAAMI Spec Max rim diameter for 45 Colt is .512, SAAMI Spec Max rim diameter for 45 Schofield is .520. I just grabbed a bunch of Starline 45 Schofield cases and they are running pretty close to the max at about .519-.520. Grabbed some Starline 45 Colt and they are running around .508-.509, a bit under the Max.
Most modern revolvers can handle the larger rim of the 45 Schofield just fine. Except the 'original model' Vaquero. I have a few of those puppies. There is less clearance around the ratchet teeth on the old Vaqueros than there is on a Colt or clone. That is because the ratchet teeth of the old Vaquero were cut from a simple circular boss, while the ratchet teeth of the Colt and clones have a scalloped design which affords more clearance around the cartridge rims. Cutting the teeth the way Ruger was cutting them involved less machining steps, most likely that is why they did it that way.
One of my 'original model' Vaqueros absolutely would not accept a 45 Schofield round in one chamber because of this clearance issue. They chambered fine in the other five, but would not chamber in one hole. Yes, something was slightly off in dimensions, but there you have it. A few minutes work with a file remedied the situation, but as built, that gun would not accept a 45 Schofield in one chamber. (I happened to discover this problem at a CAS match. Luckily I had a file handy and spent some quality time with that revolver during lunch break)
Here are a couple of photos to illustrate the problem. In this photo, the cylinder on the left is from the 'original model' Vaquero. You can see how little clearance there is for the rims of both 45 Colt and 45 Schofield. The cylinder on the right is from a 2nd Gen Colt. If you look closely, you can see the 'scalloped' shape of the ratchet teeth on the Colt.
I recently bought a New Vaquero chambered for 45 Colt. Ruger apparently learned something from the shape of the 'original model' Vaquero ratchet teeth design and has cut more clearance into the teeth. More machining required this way, but there is plenty of clearance for both rounds.
I never buy commercially loaded 45 Colt or 45 Schofield, I load all of them myself. Usually with Black Powder. But the other guys are correct, if you are looking for factory 45 Schofield ammo it is harder to find, and probably going to be more expensive than 45 Colt. And as far as I know, 45 Schofield is only available in Cowboy loads, while 45 Colt is available in all kinds of loadings.
Probably much more than you wanted to know, huh?