Gun freaks

Ammoman.com (inexpensive!)

Fulton Armory (where I get my Black Hills match .308)

Bewbs (had to throw that one in there to satisfy SOME people)

MidwayUSA.com (probably the same as Natchez right now)

Sportsman's Guide

Cheaper Than dirt

Haven't used them myself, but a friend at work recommends Georgia Arms.  They have great prices on bulk ammo.

Georgia Arms

I've used some of the one's mentioned but here is one I've heard positive things about.

http://www.ammunitiontogo.com/

What are you looking for?

When I was buying such things I picked up some ammo from them---decent stuff!!!

I buy all my ammo from cheaperthandirt.com

If you want to go .223 in your 5.56 I found this one:

.223 Remington Federal American Eagle FMJ 55 Grain 1000 Round Loose Bulk Pack 3240 fps  $399.97

Or if you need a true 5.56 I'd go this:

.223/5.56 NATO Lake City M855 FMJ 62 Grain Steel Penetrator 1000 Loose Bulk Case 3025 fps  $599.79

That too, also even if it's marked a certain price you can ask them to come down on it and sometimes they will.

Sgammo.com

http://sgammo.com/product/federal/1000-rd-case-556-223-lake-city-green-tip-62gr-m855-penetrator-loose-ammo

Luckygunner.com

Sgammo usally has the better price.  It has jumped and supplies dwindled since last Tuesday.  Also there is a palce in texas cddn investmnets that has a nice supply, usally.

I'm sorry but the location of my armory is top secret. I could tell you but then..... well, you know.

sgammo.com

Same ammo for $399....that's $200 cheaper

this, but I get it shipped. Always have something on sale and it usually includes a dry box with it. 

 Questions on reloading. Once you own your brass, what does it cost you per round for a .223 plinking round? How much more for accurate target rounds? Is 7.62X39 worth reloading or are the steel cased rounds so cheap it's not worth the effort, in your opinion of course.

If you buy enough, you can get 223 bullets down to about 8 cents each, primers for about 2 cents, and about a nickle worth of powder