What about the 500 S&W Magnum?
From Wikipedia:
the [.44 Walker was ] most powerful commercially manufactured repeating handgun from 1847 until the introduction of the .357 Magnum in 1935
S&W .460 Magnum has higher velocity. 200gr JHP @ 2400 fps. Thats faster than a lot of rifles.
Same frame. 72 oz, empty, for the 8 3/8 barrel model.
I love my .460XVR.