I'm not that big into varmints but I want to be, just can't find the time.
I have two rifles I bought as light deer rifles and varmint guns, one is the Savage 12vbss and the other is the model 25 classic, and though I don't own a Cooper I doubt my Savage's would take a back seat to one.
The model 12 weighs about 13 lbs with a Weaver V24 scope and the model 25 will probably weigh about 8 1/4 lb with a Simmons 4x12, so one walking and one sitting.
Both have 1-9" barrels and will handle the Speer 70 gr simi spitzer which is likely the best .224 whitetail bullet ever designed, although this year I'm going to try the Sierra 65 gr Gameking which is supposed to be designed around whitetail deer size game