I have some 460 S&W cases coming to make some 45 Colt shotshells. I have a question about the sizing down process to get the brass to fit into the chamber throats. These will be shot in a Uberti SA. From the way the sized cast bullets push through the throats, they measure approximately .453. The most popular dies are the 44 Special/44 Magnum. I measured the neck wall thickness of a couple .44 cases, and they measured .012. So, if you take the .430 bullet diameter + .012 + .012 for the two neck thicknesses, that adds up to .454 diameter.
According to the book specs, the neck of the .44 case is .456. So, my question is, is the necked down 460 case going to be a little bit of a force fit into the the .45 throats. Or, does the .44 sizer die neck the case down a little smaller than the books .456 measurements? I haven't gotten my .44 dies yet, so I have no way of knowing. Any help is greatly appreciated.