I purchased the Lee Anniversary kit along with their carbide dies for 9mm and .38/.357. I didn't care for the Safety Prime system so I purchased a RCBS hand primer. I figured I'd use my Lee shell holders. RCBS and Lee shell holders interchange fine in the press. I wasn't thrilled about how the Lee holder fit in the RCBS hand primer. It almost had to be forced on. On a hunch, I picked up a RCBS shell holder to see if it made a difference. The 'cone' angle underneath on the two differ. The RCBS has more taper than the Lee and fits the primer feed post a lot better. Now the minor problems I was having with the Lee holders installed are gone. Just thought I'd pass that on.