Check Sportsmans Guide or Cheaper than Dirt
I'm wanting to get some bulk in .40S&W...the cheapest I've found for a box of 100 is $20 at Wal-mart for Winchesters. Sometimes they have 180-grain, sometimes 165-grain. I'd like to get some 155-grain bulk if I can and still pay $.20 per bullet.
If you can still get it for $20/100 you better grab all they have.
I've ordered from just about everybody there is, and have never had a problem. Sportsman's Guide, Outdoor Marksman, Midway, Natchez, AIM Surplus, Hunting Shack, others I can't remember right now. Never found a true bargain, in the caliber I was looking for at the time, at Cabela's or Cheaper Than Dirt.
Just shop online for the best price (per round, taking into account shipping costs) and buy whatever is the best bargain.
Wal-Mart has the best ammo prices around, from what I've found. I think 40 here is ~ $22 for 100.
Yeah most places have it priced $13-15 for a box of $50, so I'm thinkin' $20 per 100 at Wal-mart is about as good as it's gonna get.