If you can't locate the TAP rounds locally, Academy sells .223 Hornady V-Max hunting rounds that are loaded to pretty much the same ballistics if you go with the 55 gr. ballistic tips. Of course, the TAP rounds supposedly have a low flash powder so you aren't night blinded. I had a couple of mags of those in my unit when I carried my AR.
jim's sells TAP although you'll pay out of the ass for them, just like every thing else in the store.
hebert guns on airline (p-ville?) probably sells it. i've bought hornady moly match .308 from them before when jim's stopped carrying it, give them a call.