Boy I think I have heard it all ...one of the easiest animals to kill in the woods with hundred's of thousands shot prior to the magnum craze with 30/30's and all sorts of woods cartridges and now all of a sudden a 243 won't do the trick. If I were packing a 243 and hunting deer and happened to have a black bear tag...I wouldn't waste a nanosecond ..put the bullet where it needs to go and he drops dead simple as that. That said I would use a well built bullet and that would apply to the deer also. More than enough energy and velocity to do one in on the cartridge side...