Checking a few spec (and bearing in mind that the spec are what things ought to be, and perhaps not what they actually are...)
And I'm a little confused about those who say cutting the cylinder won't work.
The AR and the ACP are the same length, .898" When you drop an ACP round into an ACP chamber, it heaspaces on the case mouth. When you put an AR case in an ACP chamber, it heaspaces on the case RIM.
The books says the AR rim is 0.090", so the mouth of the AR case would be that much short of the ledge in the ACP chamber.
You can remove metal from the back of the cylinder, say, 0.090" to allow the AR case to rim clearance to operate, and the AR will still headspace on the rim, or it will headspace on the ACP chamber ledge, depending on the exact amount removed from the cylinder, and the actual position of the chamber ledge.
The only effect this would have on an ACP case is that 0.090" more brass will stick out the back of the chamber. I doubt that small amount of the head of he ACP case being unsupported will be an issue.
The book also says the .45 Colt is .480" at the head, where the ACP and AR cases are .476". SO, putting an AR case in a .45 Colt chamber should be an .004" sloppy fit. I doubt the smaller diameter AR case would rupture, but it probably expand more than is good for it. Even at the low pressures the round operates at, I think a shortened case life would be a likely result.
And the rim diameters listed are .45AR - .516", .45 Colt - .512", and the .45 Schofield - .522"
SO, a .45 Colt cylinder might not need the ratchets cut for the .004 larger AR rims to clear, but might need to be cut for the .010 larger Schofield rims. Can't say for sure without looking at one, and I'm not going to drag them out right now.
The only advantage to cutting a Ruger Blackhawk to take AR cases is that it will let you us AR cases. That's all. ACP rounds should work normally. One possible disadvantage is that prospective future buyers might be put off by what looks like a huge gap between the shaved ACP cylinder and the recoil shield.
Can't see any reason to shave a .45 Colt cylinder unless you had a spare lying about. AR brass should work in the oversize Colt chamber, but why bother? Do it to the ACP cylinder and you get to use AR brass and it will last as long as practical.
Or am I missing something here???
And I'm a little confused about those who say cutting the cylinder won't work.
The AR and the ACP are the same length, .898" When you drop an ACP round into an ACP chamber, it heaspaces on the case mouth. When you put an AR case in an ACP chamber, it heaspaces on the case RIM.
The books says the AR rim is 0.090", so the mouth of the AR case would be that much short of the ledge in the ACP chamber.
You can remove metal from the back of the cylinder, say, 0.090" to allow the AR case to rim clearance to operate, and the AR will still headspace on the rim, or it will headspace on the ACP chamber ledge, depending on the exact amount removed from the cylinder, and the actual position of the chamber ledge.
The only effect this would have on an ACP case is that 0.090" more brass will stick out the back of the chamber. I doubt that small amount of the head of he ACP case being unsupported will be an issue.
The book also says the .45 Colt is .480" at the head, where the ACP and AR cases are .476". SO, putting an AR case in a .45 Colt chamber should be an .004" sloppy fit. I doubt the smaller diameter AR case would rupture, but it probably expand more than is good for it. Even at the low pressures the round operates at, I think a shortened case life would be a likely result.
And the rim diameters listed are .45AR - .516", .45 Colt - .512", and the .45 Schofield - .522"
SO, a .45 Colt cylinder might not need the ratchets cut for the .004 larger AR rims to clear, but might need to be cut for the .010 larger Schofield rims. Can't say for sure without looking at one, and I'm not going to drag them out right now.
The only advantage to cutting a Ruger Blackhawk to take AR cases is that it will let you us AR cases. That's all. ACP rounds should work normally. One possible disadvantage is that prospective future buyers might be put off by what looks like a huge gap between the shaved ACP cylinder and the recoil shield.
Can't see any reason to shave a .45 Colt cylinder unless you had a spare lying about. AR brass should work in the oversize Colt chamber, but why bother? Do it to the ACP cylinder and you get to use AR brass and it will last as long as practical.
Or am I missing something here???