I have an Armalite AR-10 carbine (16" barrel) and love it. I have been reading on AR15.com, and there doesn't seem to be THAT MUCH difference in barrel length. If you are shooting 300-500 yards, there will be more difference, but I won't shoot at any game over 150-200 yards so... I have only shot my AR out to 100 yards so far, but it is EXTREMELY accurate at that range (even using cheap ammo). If I wanted to shoot long range, I would go with a 24" bull barrel like the ones on the AR-10T that Armalite makes. DPMS also make a heavy barrel AR-10 that is very good quality (I would have boughta DPMSbut found my Armalite used at a good price).