I've used about 16#'s of TAC in .223. 25.2g's over a 55FMJ is what my 16" AR likes. Its good stuff, meters well and it used to be real cheap, think I paid 90-95 bucks per 8# jug.
Some people are like Slinkies. Not really good for anything, but you still can't help but smile when you see one tumble down the stairs.