I have a remington 700 sendero special in .270 w/ a leaupold vari-x III (3.5-10 power) scope.
When I use hornady custom ammunition, my groups are consistently less than one inch at a hundred yards off the bench.
You can't go wong w/ a rem. 700. The sendero special has a free floated bull barrel w/ a nice, heavy synthetic stock. Perfect for varmints and long range plinking, but a little heavy to go running around in the woods with (i.e. great for groundhogs).
I got .270 so that it would be versatile enough for me to take just about any game in north america, and while it is more than adequate for varmint hunting, you might want to go w/ 22-250 for a dedicated varmint gun. Check out
www.hornady.com they have nice, honest ballistics tables for thier ammunition. It's an easy way to compare.
Debaser: 1/4 moa @ 1000 yards w/ .223?????? I believe that would break many world records as you would only have 2.5 inch groups.