Nomercy...I shoot a HVA Carl Gustaf Custom Rifle and I' m using Federal Premiuim 165gr. Boat tails. I liked the performance of these bullets with my old scope but it was only a 4X. I couldn' t get real great groups at 200 before due to the scope power but now I' m not too sure what to expect with this new scope. I' m getting a pretty good idea now with all the good responses. I think reloads seem to be the key, but I don' t have any reloading equipment and I don' t shoot this rifle a whole lot other than at big game. I' m going to stick with the factory ammo and try a few different types.