Call JES. If he hasn't cut the chamber then ask him to cut it to 357 Magnum. Some rifle chamber reamers (I prefer Clymer's 357 Max reamer) are available with cylindrical throats. All mine have been 357 Mag chambers that were either rechambered with a Clymer 357 Max rifle reamer or were properly throated with a cylindrical throating reamer.
Bellm has experience with monoblocs.
This has been an interesting and educational exercise....and just the sort of thing I appreciate participating in 'fire discussions.
I called JES and left a message asking him to cut the chamber to .357 Magnum if his .357 Maximun chamber reamer did not have a cylindrical throat.
