Earlier in the thread I had mentioned the issue of my old Sinclair hand priming tool not seating the CCI-450 below flush in the 6 BR cases. I bought a 21st Century tool and I love it.
But since I will be seating large primers in the Creedmoor using Hornady brass, at least to start I decided to fix the issue with the tool. It has shims (Thin washers) to put under the part that holds the primer punches if it is seating too deeply, but you are out of luck if it doesn't seat deeply enough.
I took .003 off of the one for the large punch and .005 off the one for the small punch. That is about what was needed as one was longer than the other, and a hair too much is ok, because you can lessen the depth with shims.
This is the piece that holds the large primer seater stem and determines seating depth. I removed .005 from the top, re-chamfered the inner and outer edges and polished a little with 600 grit.
Here it is in the tool, you can see the seater punch is above flush as it should be.
As is with no shims it is now seating Federal 210M primers .007 to .007
5 below flush. Good to go.
I'll use the 21st Century tool for small primers and the Sinclair for large primers, no need to swap out
parts to switch back and forth, but if I should want to, the small primer part is also fixed.