Slug the barrel and measure the diameter of your bullets. Bullet to bore fit is the single most important aspect of shooting lead bullets. Size (or purchase) bullets starting at .002" over groove diameter. I have 2, 9mm pistols, one has a groove diameter of .356" and the other .357". To shoot leading free, I size bullets to at least .358".
Also, I wouldn't shoot a bullet much harder than wheel weight alloy; BHN 10-12. Bullets need to be soft enough to obturate...
My Anchor is holding fast!