I have taken 4 really nice 8 point whitetails with 158 gr. SWCs in my Python, plus several does. My all time longest handgun deer shot was a crop damage doe at 201 yds. with my Python and an AimPoint. I dead centered the rectum. The bullet was under the skin of the chest, undeformed. Probably a very lucky shot, but I'll take it.
I've also taken many deer with SWCs in .41 Mag., .44 Mag, .454 Casull, and .500 S&W. Lead SWCs with really big meplats do unbelievable damage to deer.
Be glad to share load info with you. PM me.
An interesting note: my Dan Wesson .44 Pistol Pac (4",6",8") does not shoot lead bullets very well. My Colts, Rugers, and FAs all do very well.