I have a RRA Varmint with the 20" barrel and I can't tell you how happy I am with that gun. The thing is just stupid accurate. It will shoot groups as tight as My GAP .260. At 100 yards anyways. It's by far a sub-MOA gun. I have shot everything from 50gr to the 77gr SMK with awesome results. But mainly the 77 SMK. I've even had good luck single loading the 80gr bullets.
I really don't think you can go wrong with that RRA Varmint.