I just loaded my first 10 rounds for a semi-auto. Brass was full length resized, trimmed, and cleaned. I used a 55 gr. V max bullet and 20.0 grains of IMR 4198. This is for a M400 Sig. AR-15 in .556 / .223. I did not have a small base sizing die, I used a standard set of RCBS dies. I did put a very small crimp on the bullet. I thought I would shoot one round then clean until I get these shot up. I should know if they will cycle by the time I get these 10 rounds shot. The semi-auto is all new to me. Have I over looked anything?