I was in search of 338 lapua dies until I ran into some redding neck sizing dies and bought them with out even realizing they were neck sizing dies. I have never used neck sizing dies and don't even know they're purpose. Can you guys help me out here? I talked to a few long range shooters about they're input on these dies and one told me I would be fine with what I have as long as I do not plan on using my Brass in 2 different rifle because the brass would form to my rifles chamber and another person told me I'd have to buy a body die to push the shoulder back to spec. Help please and thank you!!!