If it's a small caliber varmint round you're after, it's pretty damn hard to beat the .223 / 5.56 MM. Brass is all but free, and can be picked up on most any range. Factory ammo is available in most any grade, weight, and bullet type imaginable. The round is accurate, and comes in any action type, barrel length, and price range you could ask for.
As an example, I grabbed this Marlin X-7 this past year for a song. (I think I paid under $250.00 for it). The first thing I did with it was to ditch the cheap molded plastic stock it came with, for a nice completely finished Laminated Thumbhole Stock for it from Boyd's for $99.00, that was a perfect drop in fit. I topped it off with a Nikon P-223 scope sitting in Burris Signature Zee Rings, and it shoots into one ragged hole for as long as I want to sit there squeezing the trigger. (Which is very good by the way, and similar to the Savage Accu-Trigger). I doubt I have $400 total in the whole rig. From a cost standpoint that's pretty hard to beat. That's just one example of how far your hard earned dollars go with the .223.
