Another shooter who shoots a 22-250AI suggested I try his load. In his rifle it has a 12" twist rifling. Mine 8" his rifle with 37grs of WW760 produced 3,700 FPS with 65gr Berger. His BBL is a 29" ( ? Brand) Mine is a 26" Rock creek 5R. That same load ( Sierra 65gr Game King)produced 3300 FPS with very poor accuracy.How just 3" of BBL produce 400 FPS faster? Then I tried 44grs of H4831SC and that load produced 3,625 FPS and best accuracy ever. Less then 1/2 MOA ( My rifle is a Cooper Classic sporter stock and BBL) So whats up with that?