FWIW, Good choice. I probably dont need to tell you this as I think you got 10x more experience than me on these projects. The industry makes pull through reamers. I did a garand with one becasue I could not access the chamber from the rear. It worked real slick. the bolt follows the reamer and when the bolt falls - done. Or, You can stop just a nit before the bolt is all way down to cut a min chamber. Not for DG, but; just saying there is that flexibility with the visual feedback.
If I had a Ruger RSM in 450, I would be thinking long and hard about letting that one go.
