I've been hunting whitetails with a 44mag and am loving it. I have a Remington Super Redhawk with a 9.5inch barrel with a scope on it; sometimes I'm almost not sure it qualifies as a pistol it's so huge.
I've had no issues with it during hunting, and have taken 5 deer in four seasons with it. Two of these ran less than 50 yards after my shot before dropping, and the others just dropped right on the spot.
It did take a little getting used to though, since a pistol is a little harder to stablize for a shot. The first deer I took with it was a spike buck, after my shot I could see an exit wound (so I thought), but he just ran about 20 yards or so, and stood still again. I decided to try a head shot to finish him off without wasting any more meat - and with that shot he dropped in place. Come to find out, my first shot only grazed him (creating a red spot on his back I thought was an exit wound) and my second shot (when I was calmer, knowing it was just a followup shot) had nailed him in the head.
Hopefully I've gotten more accurate, but still feel the gun is more accurate than I am