I bought a Mossberg ATR-100 in .270 at Wal-Mart a few years ago. I put a nice Leupold Vari-X III scope on it, and it has shot 1-1.5" groups with Federal Fusion ammo consistantly since I bought it. With handloads, it is right around an inch consistantly.

The trigger is pretty nice, and, for a rifle I drag up behind me into a climbing tree stand, I couldn't be happier. As an added bonus, the rifle comes with a scope base already installed, so you just need a scope, sling and rings to be set for hunting.

As for the caliber choice, the .300 H&H will kill a deer, but so will a .270. If you don't mind the recoil of the .300 H&H, then use it and save the money.