I'd say that any round is fine for killin varmets
but if your getting a .223 I'd say go for it because I've shot coyotes with one before and never had a problem with it. I'd have to say that I've had the most fun shooting coyotes with a .223
My uncle buddy just got a new Ruger one. i dont know which model and all that but I just know that it was a good smooth rifle with a deadly accurate shot.