I bought some used competition Rcbs dies for 308win. Ive only been reloading for about 6mths so bare with me if this dumb question. I cant seem to get the bullet seated accurately everytime. Im seating the bullet to 2.820 but Ill get some that are 2.821 or 2.19.5 sometimes 2.17. This really pisses me off that I cant get them all the same. Is this something that everyone experiences?Im useing a Lee press and Im trimming all my brass to 2.08.