Something else to try, is pre plug the cavity with Paraffin, or any kind of stick boolit lube. HP's are dependant on hydraulic pressure to work. If they become plugged with a "non hydraulic" material, Ie. clothing, wood, etc, they don't work. They don't work if the nose folds over preventing any liquid from entering either. Pre plugging with something that goes hydraulic under pressure assures expansion. Some of the "new" high tech boolits use this very old idea.
http://i254.photobucket.com/albums/h...3/IMG_3149.jpg Pre plugged with LBT Blue Soft lube.