ORIGINAL: bigbucks98
Depends on the varmint but my two favorites are the 204 ruger and a 223 AI. I shoot 52gr. Berger V-max for the blow ups and A-max but thats cuz i hunt fur.
The V-Max and A-Max are Hornady bullets. I'm a big fan of the 55gr Nosler Ballistic Tip for my .22-250. Always very accurate, and they blow up nicely on impact.
Mike