I have a Rossi 38/357 single shot rifle in that the owner wants threading.
I've just checked the bore and there's a clear bulge about two inches forward of the chamber. While the bore is bulged the bulge does not extend to the barrel exterior.
I've had a Marlin in the same calibre with two bulges and I put a new barrel on it.
The military standard for bulges in .22 rimfire rifle is two bulges are acceptable providing the rifle passes accuracy testing. Conversely for a 7.62mm any bulge and the barrel is replaced.
This leaves the question of whether to replace the barrel on the Rossi. The owner will be shooting at the lower end of the velocity scale at about 800 fps as the rifle will be moderated and the rounds kept sub sonic.
Highland Outdoors import Rossi's but not the single shot model so it's uncertain if a new barrel can be sourced so it may be that the rifle gets scrapped.
Anyone with experience on Rossi's and bulges care to comment?
My preferred option is to fit a new barrel but getting one may be problematic.
The other answer is to have it re-proofed and see if it passes but I'll take experienced advice before I go along that route.