I had the same issue with my .308. I was using regular dies. I ended up setting up the sizer die so that at the top of the stroke, the shell holder was touching and slightly camming over against the die. I used to run it all the way up, thread the die in until it touched, and then back it out 1/8 to 1/4 turn. After camming over, it has been a night and day difference!
Unfortuntily, I had about 500 rounds already primed, so I removed the decapping pin, and ran them all back through and wiped off the lube by hand. What a PIA! Oh well, I guess that's how you learn.