I did trim the brass to the specified length with a Lee case trimmer, so the starting point should be good in that respect.
Then as you have probably garnered from this thread, there is a problem with your sizing process.. Or the bullet is in the lands on one of the rifles with chambering issues. You could also have your seating die set too tight as well, which will bulge the shoulder, making it difficult to chamber. If that is happening, you can usually feel that when you seat the bullet.
