Today I received an RCBS .357" H&I die for use with my Lyman 4500 Lubrisizer. It wouldn't seat all the way in the 4500's well. I did some measuring and just above the bevel at the bottom of the RCBS die, the barrel was .003" larger than the Lyman die I had just removed. The difference was enough to stop the RBCS die from seating properly.

The solution was rather simple: I used my grinding wheel on the fine side and rolled the die on the plate with a finger to keep the metal removal as close to symmetrical as possible. I didn't touch the bevel as that's how it seals at the bottom.

Now it works as advertised and this is the first RCBS H&I die I've ever had a problem with in my Lyman Lubrisizers.

If anyone else has the same problem, that would be a good place to begin checking.