The post is suppose to focus fluid pressures outward producing a large mushroom with a shallower hollow point than others. Giving a combination of stopping power and deeper penetration. I saw a pig taken with a 158 grain 357 round at about 8-10 yards. Quite impressive even if it did not leave an exit wound! What I like most of all is it seems to group closer to my ball ammo than the other Self Defense ammo. And much more accurate than my Gold Dot ammo.
