How about a 9.3x82R? If so, it wouldn't hurt hurt to shoot 9.3x72R in it - sort of like shooting a 22 short in a long rifle chamber. Whoops, I see now that the chamber may be shorter or slightly tighter but what I don't see is where the rifling begins. Using Cerrosafe instead of wax would give a much better idea of the chamber, especially if it was blocked long enough to include a bit of the rifling. The key is the length at which the rifling starts.
I'm leaning that way. I still have a lot to learn about reloading though. I'm unsure if i'd be too much pressure/bolt thrust if i reamed it to 72r
Sounds about right, I think the 57R case is the most common after the 72R and 74R variants. You should be able to trim 72R brass to 57mm and fire form. I'm not to familiar with the ballistic on the European variant but from the proof marks I believe it calls for a 283 grain bullet at about 1650 fps. Very similar to the .360 2&1/4" NE.
SKB, after googling your suggestion i found:
https://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=405731&page=1I'm going to cerosafe the chamber. I believe you are right on the money
