I have hunted yotes in western NY for a long time and have had my share of tough dogs but not too many.

I normally use a Savage model 11 .243 Winchester MAg with 95 grain teflon tipped remmington ammo. Knocks em down in thier tracks everytime unless I screwed up the shot.

If I am hunting a wooded area instead of a field I'll switch to a 12 gauge with number 2 or 0 shot sometimes 00. They run a little further then but not that far.

As far as tough dogs go I have one that sticks out in particular so much so that I got this one mounted (life size).

I was out deer hunting and kicked out 2 doe I ran around a little knole to get off a shot at one and heard them comming out of the brush. Instead of the deer out came a nice looking coyote. It was about 20 yards in front of me so I pulled up and shot. I was using a 12 gage loaded with federal 3" slugs. The dog never even flinched he just sped up.

I couldn't belive that I missed, but I walked over to see the trail in the snow and saw a small splatter of blood. The longer I followed the trail the heavier the blood trail got and I caught up with the dog in a swamp 150 yards from where I first shot him. He was dead when I walked up to him and I found that I hit him good. A slug through the front shoulder and exited the chest. I have shot deer with worse shots than that and they went down quicker.

I was pretty impressed with the strenght these animals have.

The size of the shot is the problem. I used BB shot when I hunted coyotes in Utah. I liked a shotgun better than a rifle in the country I hunted. BB shot rolled them out to 45 yards (full choke, 3" mag, 12 gauge). A hunting partner used a 10 gauge, BB shot, 3.5 mag. This was a 50-60 yard gun. Jus like every other game animal, from rabbits to elephants, it's where you hit them that's the most important. What you hit them with has to get to the boiler works, but you have to hit the boiler to put them down.
Dr Fatguy

i had one i shot 3 times witha slug one in the lung 2 in the belly he ran 4 miles befor he died when i got to him he was still breathin put him outa his misery and made him into a coat another one we hit with my 350 ford superduty on the road during deer season he ren in frount of us and got hit good we followed him for 5 miles and blood was everywhere then he started limpin away finished him with my 12 gage

He will eventually die of lead poinsoning. Possums are tough shells to crack too. My cousin and I had one in a trap once and we thought it was dead, when my cousin went to get it out of the trap the possum went for my cousins face If I hadnt emptied the 10shot mag from my 597 .22, that possum would have tore my cousin to peices.