The 50 and 55grn 223 loads are popular for coyotes because they're about the perfect balance for killing power and fur-friendliness and trajectory.

My wife's been shooting Hornady "Factory 2nd" 75grn A-Max's in her Savage 12 a bit this year, only taken a few dogs this summer/early fall with them. They're a bit rough if you hit anything hard.

Barrel length and twist matters a lot for the heavy pills. They're disastrously slow and not properly stabilized in my 1:9" carbines, but the 75's shoot fairly well in 24" and 26" 1:9's.