Buffalo Bore loads their ammunition up to maximum SAAMI specifications, which delivers devastating performance on a wide range of game. Please note that this ammunition is not intended for older guns. It is made for modern firearms only, as some of the ammunition could damage older and weaker firearms. Both the Magnum and Lower Recoil versions of this ammunition are designed to kill game animals in the 1500 lb. class and yes this 350gr. JFN bullet out-penetrates the 405gr. JFN bullet, due to its tougher construction and therefore smaller mushroom—expect around 48 inches of penetration in living flesh and bone. This ammunition is new production, non-corrosive, in boxer primed, reloadable brass cases.