I Have a s and w m24-3. Bought new. I really want to shoot lead slugs but Have been having leading problems. Have tried gas check 429215s, 250 rcbs keith, 240 plain Base h and g. Sized at .428, .429, and .430. All lead with 5 rounds shot. This is just where the boolit enters the barrel, both lands and grooves. I tried to slug the barrel but having difficult time getting a good reading. Thanks