Is this a new rifle? or used? a short barrel ECT., ECT., different strokes for different DPMS pieces tell us what you have, is it a factory Rifle? was it built by someone, who when , what do you know, can you post pictures?,,. before you buy any large amount of ammo try 20 to 50 rounds of various available rounds. Shooting a .308 does have an amount of expense associated with the beast. FROM One Newbie here, to another Newbie: Hey!... you are a newbie here, hang around awhile, and these guys will get you the info that you need You input info, they ask for more info and that is how the process works, don't be a smart ass, these regulars will see right thru any trash you shoot at them, be honest and above board with them. I have been here almost a year after buying a new DPMS LR308 Oracle rifle and read the manual (I am new to the platform) I am an old retired gunsmith on Hunting rifles, wheel guns and 1911sM1 Garand, M14 M1A, M60, and even an Ruger Mini 14 owner. I knew Nothing, Nada, Zero about the 308 Ar, Ar15 or AR 10 now I am starting to learn, reading helps but mano to mano cuts thru the fog.