It really just depends on your gun. I personally have a Winchester 1300 youth model with a 21-22" barrel and I've tried a Tightwad .570, a Carlsons .575, and a Hastings .562 in my gun and so far haven't broken 135 hits in the 10 at 40 yards. But, in some other guys guns that Hastings puts up 150+. It's all just whether your gun likes it or not.