I took a buck with my 22 Hornet a few years back. I shot it in the lungs with a 45gr. hollow point and it absolutely flattened the deer. When I gutted him it looked like a grenade went off in his chest cavity. I wouldn't hesitate to shoot another one with it. It's all about shot placement.
I got a new 22-250 and I plan on using it this upcoming deer season. 22's are very effective on deer sized game with good shot placement.
Spanky