Recently got an AR that I am trying to load for. I have not yet sent a reloaded round down the tube. I have read that small base sizer dies are recommended for the autoloaders, and I have also read that FL dies are good for an autoloader. This has caused a little bit of confusion, so my thoughts are that I will start with the FL sizer and if I run into problems I will get a set of Small Base dies. My question is about how deeply to run the the brass into a full length sizer for a gas gun. When setting up dies for a bolt gun I used a FL sizer that would just set the shoulder back a few thousandths. When doing this the shellholder did not come close to the base of the die. I tried following the directions that came with the Lee dies and do not understand them. The instructions read that the die should contact the shellholder at TDC, then be screwed in another 1/4 turn. This makes no sense to me because it seems that all this will do is cause more stress at the top of the stroke, but will not size the brass any more. Is there a way of FL sizing the brass without using a mic gauge, previously I have done this based on bolt pressure and do not see how to accomplish this with the semiauto.