I tried 250 gr. in a sabot. No luck. Would not stabilize. Went back to patched round ball which makes cloverleafs at 50 yds. with 70 grains of Triple Seven. If I use one of them old plastic round ball patches I can go up another 10 grains with out blowing the plastic patch for same accuracy. I am meaning to try some lighter Minnies in the 300-400 grain range some day but I only put it on the frame once a year to shoot it. Beautiful light barrel you can carry all day.