I can tell you that the .204 with 32 gr. Sierra bullets is no go for coyote. For coyote your AR is an excellant choice. That is what I carry most of the time. When expecting long shots, 300 yrds. and out, I like the .22-6mm. The guy I hunt with also uses an AR for up close and personal, but he switches around for long shots. He may have a .22-250, a 7mm mag, or a 300 WSSM. I did pick up a .204 upper and may give it a try on coyotes as you just keep shooting as long as their moveing with the AR, and even less chance of a rickochet.