I've been hunting whitetail all my life, and with a .44 mag for the last 25 years. If one of the previous posts is correct in that a 10mm has over 1,000fps and 500+ ft/lbs at 100 yards, then I would have no problem taking a 100 yard shot. I'm confident I could make a good shot at 100 yards though b/c I've been hunting with a handgun for a LONG time. If you can make the shot, the 10mm is capable of making the kill.