There is an incredible selection out there that perform quite well on coyotes. You need to ask yourself some questions though that will help you in your selection.
Am I saving fur? (not really an issue with the 223)
How far is my comfort zone in shooting?
What twist is my barrel?
I generally hunt coyotes at night and shots are almost always under 150yds- usually much MUCH closer. I save fur. I have on occasion during day unts shot a dog at 300yds plus, I am comfortable with that. My twist rate on my barrel is 1x9. I shoot midwest dogs which are a little bigger than the SW dogs. So, based on my operations, I opt for a 60gr HP flat based bullet in my reloads for 223 remmy. Hope this helps.