WOW! Not trying to get in on the arguing, so I will just post my opinion. The AR10 is a great platform, but for a coyote gun, it is a little heavy. Personally when I go to my spot to call some song dogs, it can be a long way, and want lighter weight. I would, and do use a 6.5 Grendel, or 6.8 x 43 in an AR15 platform.

There is alot of discussion on the internet as to which is a better cartridge, and have seen arguments for both sides. Myself I prefer the 6.5 Grendel as I like the ballistics and performance better. On that note, you had better reload if you go with that cartridge as factory ammo is scarce, but the componants are abundant.

The 6.8 x 43 (SPC & SPCII) is also a great cartridge with easier to find factory loaded ammo.

I have built both calibers in the AR15 platform for my customers, and all are extremely happy with the performance of what they choose.

Here are some pics of my 6.5 Gendel (OD green one w/scope) and some pics of a 6.8 x 43 I built (Black one)

Hope this helps and doesn't add more confusion in your search for a coyote gun.