I've killed several deer with a 338 WM and 200 gr. factory ammo. The shots were inside 100 yds. The only difference I could see between the 338 WM and an 18-wheeler was the fact that there were no tread marks on the deer. The only reason I used that rifle at all was because I had some issues with my normal deer gun at the time, and I'd just used the 338 for bear hunting the previous week.