I ran mine out to 1200 yards, and back, it tracked like a champ.
You may want a zero-stop kit for it, they are about $20-25 on e-bay. The guy posts on here, Sniper's Hide, and other shooting posts - most seem happy with his product.
I will check out the zero stop for sure... Are you referring to the washers that go under the turrets that make them "bottom out" and prevent over travel?