Just my two cents here folks, but I would be a little nervous about using lead round balls in any rifled barrel. Especially those that are expensive, or ones I've invested $ into,...tunes, trigger, etc. If the barrel is tapered or chocked, wouldn't that squeze the ball out of the muzzle and deform it causing eratic accuracy? I don't know. However, I would gladly try them in a gun like the Gamo Viper that has a smooth bore!!!! tjk