Shoot your chosen round into a half gallon orange juice carton filled completely with water. Back the target with a long box (approx 24x8x8") packed full of pillow stuffing, preferably before shooting the OJ carton
. If the bullet measures around 0.65"-0.70", you have a 'winner'. All JHPs that expand within this range will penetrate 12" in calibrated ballistic gelatin. More expansion gives less penetration and less expansion gives more penetration. Good luck... Tom