Thread: Baikal single shot rebarrel - Anyone done this?

Usually , if you want to do an accurate job, you need a few gunsmithing tools like a proper chamber reamer and it's pilots and gauges. Indicating rods ...etc. The requirements is a bit more than just " chucking it" in the lathe.

There was a wildcat named the 45 silhouette, which was a 45-70 shortened so that it would have a smaller chamber volume which would be perfect for your application.
https://www.cartridgecollector.net/45-silhouette

You could also create your own wildcat by using 500 s&w cases and necking them down to 458, with a bit of shoulder.