Been making 38 bullets from 9mm Luger brass. Best I can discern, expansion isn't so great. Using pure lead as a core, tried notching and pushing the velocity per Ken Waters recommendations. Also found some bullets had completely shedded the lead core. If this persists, I intend to bond the cores. I'd appreciate suggestions as to how best check the expansion. I thought building a "tunnel" filled with wet sawdust, or shooting into a tube of water, but would like to know how best to do this. Best, Dan