I just purchased a Lee 3 die set in 45 colt. One only seater sie insert came with and its ovaled for round boolits. I put my 450 bushmaster insert on the grinder and and sanded it flat so it wouldn't scrape PC off the Lee 300fn.
I'm loading the same boolit and Lee 255g in 45 colt. I'm assuming I will have to do the same or my boolits will distort with soft lead?