Typical 11" CAR isn't a sniper rifle

and because it's low MV it drops like a pile of SH*IT at long range. If you are off 50 yards in your range estimation at 600 yards, you will miss. No heavy bullet pos handload can compensate for it's inability. AR's need 20 or more inches to be flat enough, and even then, they are very prone to wind. 7.62 or better is what is needed, and that's a fact.