The bores can run big--somewhere in the .455-.457" neighborhood I would expect. I have both a Colt New Service and the Smith but they were both shaved for .45ACP and moons. They both shoot well, or at least as well as I do. I loaded some hollow base 265gr. bullets in Auto Rim brass to imitate the Eley round. Great fun!

I recently found an unmolested .455 cylinder for the Colt and hope to put it back to the issued caliber soon.

I have a Smith that has been converted to .45 Colt from .455. It shoots 454424's sized to .454 just fine. Only problem is that I have to seat them to the front driving band because if I seat to the crimp groove, they are a hair too long! I've been ,wanting to work up a similar load using .45 S&W brass but haven't gotten around to it yet...

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