Completely agree with Joe. Now there's a first, Hey Joe?Is he sure he sized the brass after cleaning it up with the 4-0 steel wool? And what bushing size is he using, on what and what chamber size. We got to have a little more info.
Use steel wool all the time never had a problem.
Joe Salt
If he had to change to a smaller bushing, it is much more likely that the case necks have work hardened, and springback is causing a larger case neck. Does he anneal, and if so, at what frequency.What say all?