I would work on getting the primers seated to flush or slightly below the base of the case before firing any of these.
What calibre are you loading?
What brand of brass, and what brand of primer?
Also what brand of shellholder are you using in your RCBS hand priming tool?
Flash hole deburring won't affect primer seating, but primer pocket uniforming can. I like the Sinclair uniformer for my brass. That said, you don't normally have to uniform them.
|