Howdy
I shoot 45 Schofields out of my Colts all the time. Yes, the rim on 45 Schofield brass is slightly larger in diameter than 45 Colt. The same thickness. As I said, I shoot Schofield ammo out of my Colts all the time. However the ratchet teeth at the rear of the cylinder on a Colt are a different shape than the ratchet teeth at the rear of a Ruger cylinder, either Blackhawk or Vaquero. In this photo, the stainless cylinder in the center of the photo is an 'original model' Vaquero, the cylinder on the left is an Uberti Cattleman, the cylinder on the right is a Colt. Notice how the two non-Ruger cylinders have the teeth scalloped out. The Ruger teeth are not scalloped, it is just a drum shape. The scalloped shape allows more clearance for over sized rims than the Ruger shape does. In point of fact, one chamber on that Ruger cylinder does not allow 45 Schofield rims to seat fully, they interfere with the drum. A Blackhawk cylinder has the same design, and might exhibit the same problem.
I am not saying you will run into the same problem, you might have no problem at all. It is a matter of a couple of thousandths of an inch. I will also say that about two strokes of a file is all it would take if I wanted that Vaquero cylinder to accept Schofield rims in all six chambers. I never bothered, I always shoot Schofields in my Colts. However there is a chance you might find a bit of interference in a chamber or two, like I did.
All my Schofield brass is from Starline and runs around .520 in diameter, most 45 Colt rims run around .512 or so. Now interestingly enough, I have an old Frankford Arsenal 45 Colt round in my cartridge collection with a reeeaaaalllly wide rim. About .540 in diameter. This is an antique round, I wouldn't dream of firing it. But just for the fun of it the other day I popped it into one of my Colts. No problem at all, plenty of clearance for that huge rim. No way it would have seated in one of my Rugers. Not enough clearance.
Why? Do you have a lot of "too short" brass to use? I feel shooting Schofield brass in a .45 Colt chamber is akin to shooting .22 shorts in a LR chamber. Doesn't "hurt" anything but not the best accuracy and besides, the hot powder gas and resultant erosion and residue belongs in the throat and parts forward, not the chamber....JMO Wink
Well, let me tell you. I shoot nothing but Black Powder in CAS. My 45 Colt loads are stuffed to the gills with FFg under a 250 grain bullet. Recoil is stout, but not too bad. But I have a couple of Remington 1858 New Model Armies that I shoot with conversion cylinders chambered for 45 Colt. For some reason, the shape of the 1858 New Model Army grip is not as recoil friendly as a Colt and I don't enjoy shooting my full powered 45 Colt loads in them. So I shoot them with Schofields and about 28 grains of FFg under a 200 grain bullet of my own design. Makes a very pleasant, mild load that still has plenty of smoke and awe. Now believe it or not, there is no problem at all with crud building up at the mouth of the case with Black Powder, everything washes away very easily, and there is no gas cutting either. As for accuracy, my Remmies are easily the most accurate single action revolvers I own, even more accurate than my Colts. Nothing to do with bullet jump in the chambers or anything like that, the conversion cylinders are made to tighter tolerances than the cylinders of any of my other revolvers, and with 45 Colt or 45 Schofield, they will shoot rings around my Colts, clones, or Rugers.
As for Smokeless, if you should decide to try it, you will have less empty space in the smaller 45 Schofield case than you will in the cavernous 45 Colt case, and will get a better and more complete burn of your powder than you will in a 45 Colt case with the same charge. Of course, maximum charges and pressures must be observed for safety.