1) Full length resize with regular FL dies for AR. I've been reloading for my AR for several years, no need for small base die.
2) No crimp.
3) I've reloaded and shot many thousands of rounds through my AR's and I use regular CCI 400 primers.
EXACTLY my experience as well.
I have several AR's and they all chamber my reloads with regular FL dies.
I do use a case gauge, and 99.8% out of 1000's pass... those that fail 99.9% are PPU cases.