If you're set on an AR10 spend the money for top quality or you'll likely be disappointed.
As for coyotes I've killed a lot both for fun & fur with a .223, 22-250, .257 Roberts, and the .25-06 and bigger. I have tried about everything for saving pelts but the best I found was a .224" Speer 52gr HP. It had a big open tip and rarely exited near or far. I had mixed results with Ballistic tips, Blitz, TSX, Varmint Grenade, etc. I'm curious about the Valkerey (SP?) for long range in .224".
