speaking of shell holders, I just got lee dies for 7.5 MAS. First time using lee dies, it was all that I could find available. It was nice that the shell holder came with it, but the opening was too small for the large primer cup on my Hornady iron press to pass through. It ruined the mouth of the cup. Luckily I had a spare, and diagnosed the problem before any more serious damage was done. Maybe something to consider, not knowing what kind of press you have.