My wife has two M&P 15-22 Performance Center rifles. One with a fixed 4x scope, one with a variable 3 - 9 scope. CCI standard velocity has been the best ammo for her. She uses the same ammo in her CZ-452 and Ruger 10-22 Target Takedown with excellent results. The CZ-452 is the most accurate, the Ruger 10-22 is 2nd, the 15-22 performance centers are next, but she loves shooting them the most.