Simple enough. Use the hunting rifle you shoot the best. I'm not sure where this whole .22 caliber for varmints came from, but if you shoot your .270, .375 H&H or .225 Winchester the best, use it. I've used the 30-30 on many things. Ditto for a 12 gauge shotgun and .300 Win Mag. The difference between a .22 caliber and a .30 caliber is .08 of an inch. Look at it this way, a .17 is a tiny bullet right? See where I'm going? you can use whatever you want, out to whatever distance your comfortable with. A .223 rem will heat up the barrel just as quick as a .243 or a .308. So repeat shots are not a good example. A .22 LR will kill a dog at ranges you can call them to, so I dismiss that argument as well. I've heard guys say a coyote can stop way out there, but from my limited experiance, I've had them almost run me over, chasing the sound of food. The trick isn't to having a rifle that will deliver a shot like a cruise missle, rather it's when and where you set up. A caller in the trees will get a coyote closer than a caller in the open field. Or a caller sihouetted on a hill top will be less likely to get a dog in close than a caller in front of a bush.