my buddy shoots the federal fusion, 180gr's under 3/4" at 100yds. Infact, i know of lots of guys that are getting really good accuracy with this load. you probably need to start experimenting with different loads/bullets which is a common thing with guns. eventually you will find that load. shouldn't make a difference dirty or clean, i suspect that when you mention dirty the barrel is hot and after a few rounds and clean is cold. regardless, put those loads away and try different one's and you'll be surprised.