Heavy bullets in an AR-15 Carbine 1:7

[beltfed]

Beltfed: If you don't mind me asking, what brand of primers are you using?

I favor Federal 205m, but will run CCI BR4 and standard Winchesters Small Rifle as well.
There is noticable consistancy in velocities with the match primers over standard primers and the Federals have been the best for me.