Coyotes can be hard to put down. I've shot them with 60, and 55 grain sierra's and had them get up. When I got close enough to see the damage from the 60 g was extensive, but the bugger still required a second shot. The front shoulder was just hanging by the skin and the bugger still got up and started running! Shot one with a 50 grain v max at very close range, which put him down for the count, hit him just behind the shoulder quartering away. This seems to be the best spot to hit them if possible, puts them down for good! The 243 wssm puts them down hard every time though, but if the shoulder is hit, the pelt is trashed. That is why I like to stick with the 223. I have some 65 grain sierra'a and 60 grain BT's on order, I have heard they are both a tough bullet and will hopefully ensure one shot kills!