This is a .257 slug shooter i built on an air force condor. custom valve, 32 inch barrel, carbon fiber shroud, heavy hammer spring and 115 gram heavy hammer. i have had it up to 185ft lb with 85 grain slugs with room for more power, but i keep it throttled back to about 142ft lb with 65 grain cast (about 990fps) to save air. it shoots sub M.O.A at 150yds, which is as far as I have had the chance to shoot it so far