I've been having some trouble with ballistic tip ammo on coyotes. I've switched to using nosler partition 60 gr. bullets and am knocking them stupid now. The ballisitc tips were splashing on coyotes if I had to do anything more than shoot them in the neck or broadside boiler shots.
For factory ammo, I'm not sure you can buy partition ammo and if you can, it'll be EXPENSIVE. I hear good things about the winchester white box ammo. I think it's a hollow point bullet. I'm sure there will be some people that shoot it chime in soon.
I know that Federal makes soem 223 premium stuff that should do well. I just am having probles with the 22 cal. BT bullets not getting the job done consistenly. I've killed a ton with them, but I've not been happy with their consistent killing odds. Black Hills makes some fine loads. Maybe give them a call.
You'll love the R-15.. I've been hunting coyotes for 20 years with a bolt gun and have done well and still like them better. But for efficient coyote blasting, I suggest the semi auto guns. I picked the R-15 because I'm a huge remington man and the also like camo finish..!! Good luck with yours..