I just started shooting a 240gr sierra MK out of my 300 win. mag.When I seat the bullet I cannot get a consistant C.O.L.,it varies + or - .005".I am using a Redding competition seater die,so I know my die is not the problem.All of my cases are trimmed to the same size.The wierd thing is,I can load my 110gr v-max's into the same cases and get consistant C.O.L.'s all day long,it's just the MK's that are giving me fits.I have to seat them all long ,and them seat each one with a different setting on my die to get my desired length,what a pain!Any suggestions?