I generally run the bullets for poly rifling heat treated, the same goes for Colt 1911's, 1917's and Smith 25-2's. Sized snug to the throat. If that's not doable, at least over groove.
With my present alloy it Brinell tests at 28.
The key to cast in shallow rifling is eliminating the stripping at land engagement which is done by shooting the largest bullet diameter that ALWAYS functions and as hard as alloy as possible.
A powder coating may eliminate the leading, but it won't account for the accuracy loss of stripping on the lands.
