Hi Rich. I'm kind of new to handgunning and the bullets to use for which game but have taken a cow elk and a heifer buff with hard casts out of my Redhawk 45 Colt. While they penetrate well, they effectively acted like solids and both animals while taken were not dropped as quickly as I would have liked.
I plan on hunting whitetails this winter and have been loading and shooting the Horn Leverevolution 225-gr because I'm looking for something a lot "softer" than I experienced above. However, in plinking with them (~ 1200 fps) they seem to have the toughness of an tossed aspirin and a SD not much better in 45 cal. Many have come apart shooting into soft wood at about 25 yards.
That's to say I would have guessed that the horn XTPs to be about right for deer.
