I dont see this stuff around very much at all, so I figured id spread the word.
The 64gr is probably more popular, but I noticed the 55gr still made the Doc’s list for good SD ammo
Little pricey, but still under $1/rd
http://www.sgammo.com/product/speer/20-rd-box-556-x-45-speer-gold-dot-55-grain-gdhp-24455
I get took delivery of 100rds, only opened one box to check them out, there were a few dings/dents in the brass but I think that is to be expected for production ammo.
http://m4carbine.net/showthread.php?p=1120341
Found a thread that might help with the answer(s) you are looking for.
Also the ammo thread has been update.
No dents or dings in a case of it I had. Reliable function, compatible enough with some economy training ammo.
I am curious to know how this ammo performes, any personal experience?
just saw this oops thx for the info 
I am going to speak my mind about this even though this post is a few weeks old because I have been looking for duty 5.56 ammo for months. There are no reliable sources of it. Thanks to the OP I was able to buy a little for the purpose of keeping my home defense gun loaded. That it is mentioned by Doc tells me that it will work as intended.
I sincerely hope that a manufacturer will pick up the slack and start producing 5.56 loads for civilian purchase. I don’t need a pile of it, but all of the true 5.56 I buy seems a bit hotter than the .223 that I have bought. It reminds me of the old idea of practicing with 38 special ammo and carrying with 357 loads.
Additionally I don’t want to rely on XM193/855 or handloads for self defense in my home.
What a pain to buy a good carbine and have almost no real loads available for it.
Optimal choices meeting known-good specifications are always best, but there is no shortage of expanding rounds capable of getting the job done.
I disagree. There are almost no 5.56 loads for civillians featuring non FMJ/SS109 projectiles available.
Who cares? I’m fine with .223 premium loads. They run a little smoother in a carbine and will definitely let the air out of a bad guy just as quick.
I care because I have a 5.56 chambered carbine and 5.56 self defense loads are uncommonly available for civillian purchase. I do not buy 223 ammunition designed for hunting as I do not posess a 223 hunting rifle.
I am done with it anyway, I have what I need.
OP thanks again.