"Whatever shoots best out of your rifle"
+1
Every rifle shoots different ammo differently, my brother and me have IDENTICAL .220 swifts, mine shoots 45 gr best, while his shoots 42s best, any 22-250 bullet weight is sufficient for 'yotes (I use 50 gr), that is my main dog gun, both prairie and song dogs, I have taken coyotes at pretty long distances with some pretty light bullets, basically find whatever weight shoots best and it will work