I can't speak for local to Indy but I'm on the same quest as you. I've found that some of the best deals are at the gun shows (i.e. Indy 1500). I'm going to look there in March for .223, 9mm and 7.62x54. I've found really good deals on ammunitiontogo.com but the shipping isn't great. I keep an eye on slickguns.com too for any deals on ammo.
Of course, the more you buy, the better the deal is.