I was wondering how I could find out what bullet weight the rifling was optimized for. I recently took some 180gr. Berry's Copper plated rounds to try them out. At 25 yards I could barely keep 5 shots on a man-size target, including the arms! I went by the Lee 2nd Ed. loading manual, and used Power Pistol. Don't have this much dispersion with lighter bullets (165gr. Berry's) and 700-X powder.