I purchased a lee 4 die set for my .308 I have never had a 4 die set before. I am shooting from a bolt gun so I don't believe that I need to crimp. The seating dies are labeled A1 and E2 which one is the better one to use. I believe one is a seating die and the other is specifically a crimp die. I don't know if it makes a difference in which one I use just looking for some feedback