Is that seating plug pretty rough inside? I had to smooth out a few RCBS sets now for a different brand. Easy enough, just wish they’d come ready to load instead of needing polishing.
I have not had that happen to me and I load Hammers for 4 different calibers.
6.5 Creedmoor - Hornady Dies
7mm-08 - Hornady Dies
7mm Rem Mag - RCBS Dies
30-06 - RCBS Dies
I have noticed that the RCBS dies leave a noticeable seating ring.
With all of the different bullet profiles available today it is very difficult for manufacturers to get a “one size fits all” seating stem. I had to buy a different VLD profile seating stem for my Hornady 6.5G dies the other day, and I STILL had to bed the stem to seat the 129 ABLRs without damaging them. I used JB Weld after scuffing and cleaning/degreasing it well
I replaced my RCBS seating die with a FA universal, which comes from the factory with VLD-type seating stems. I was going to get a VLD stem from RCBS, but couldn't find them anywhere and I like the FA universal die a whole lot.
Good luck on the polishing -- take it from me and use a fine-grit lapping compound, NOT a valve lapping compound that you had laying around from rebuilding an old motorcycle...