Quote Originally Posted by GRA556 View Post
This is true. The USAF recycles parts all the time. I know they were doing this back in the 80(s) when I was in and I would not be surprised to learn that nothing has changed much.

One thing I remember very well is the use of the single heat shield and double heat shield hand guards on the carbines, as well as the moderators. It's almost like no 2 were alike. Only E-5(s) and above had them.
Yeah the GUUs were apparently really inconsistent. Slick side, A1, and even A2 uppers, pencil or M4 style barrels, anything goes.
I'm no USAF expert and basically picked the GUU for a build because of the apparent ease of getting it "right" rather than any particular connection to the Air Force. My grandfather served in the USAF in North Africa, where he enjoyed his meals of camel meat and warm beer, but that was long before the GUU or even the AR period.