Don't get me wrong. I love the AR, probably put more rounds through one than anything else. But for a coyote rifle I prefer the balance and accuracy of the bolt. I sit on the ground on a stadium chair, and I can shoot with the sitting bipod. I killed over 400 coyotes in AZ over a 12 year period, and this is what worked best for me. This is actually a 25/06 Sendero, but pretty much the same setup. The 25/06 was too much gun, and too noisy.
This particular ranch is near Picacho Peak, one day we called 18 coyotes and killed 12, wounded one we could not find. The 223 was more than enough for 300 yard shots, and you could keep calling after shooting and they would still come in. Bigger calibers seemed to spook them.
Between me and my friends we killed over 120 coyotes on this ranch, they were thick as flies and ate the owners cows. After he died and the cattle got sold off, it was hard to find them. That was one of our secrets, to find coyotes we looked for cattle.