Originally Posted by
MassiveAttack
Given that the reccomendation for AR's is to use small base dies and full length size everything I would be heasant to not fully size your cases and fail to see how you could have oversized the cases. Trim length won't matter as it's the shoulder that determins how far into the chamber it goes not the trim length.
Whatever you do don't change to Federal AR primers as they are harder than standard so more likely to hangfire.
The first thing I would look at is your trigger \ hammer spring as I changed to a tinmey trigger and now have light hammer strikes leading to misfires...