222 holds a special place with me. Killed my first called coyote with one in a model 700.

204 would be my second choice. Fast and flat. Thumps them dead and the kills I had with mine did not exit. The insides were turned to mush and dead in the tracks. Hard to find factory rifles that aren’t varmint profile barrels though.

223 works but it’s just common and plain. There will be more options in factory rifles and ammunition though. I have a couple 223 rifles. My favorite is by far a model 7 predator. Light and fast handling. Pair it up with a low power scope and a good reticle (German 4) and you can really pick up the hard chargers.