Judging by this
and the fact that the article is written at an, at best, 8th grade level, I'm going with "no."From: Anonymous Source
Sent: Monday, March 19, 2012 8:27 PM
To: The Americas, Israel & Europe
The last time I was there, I would be surprised if my local Cabela's didn't have 20,000 rounds of .223 on the floor. Walmart also has a good supply.
Ammoman has plenty: http://ammoman.com/c/8/223-556 (and at good prices! Dang, I might have to stock up myself!)