Just wanted to share some more pictures with you guys, these are from early 2008 in Afghanistan. This weapon "belonged" to an Air Force Second Lieutenant who was coming on one of my convoys, he simply referred to it as an M4. We know better, though.
I'm referring to it as a GUU-5P, because I suspect that's probably how it's classified, but I haven't got any real way to confirm that.
Unfortunately, it doesn't show in this photograph, but the barrel was in fact 1/7, making a 723 barrel.
What's interesting is that the lower is obviously not a rebuilt 604 or any other military model. It's a commercial M16A1 lower. If I had to put money on it, it looks like a re-barreled R653 purchased COTS. The upper has the "C H" forge mark, common on 653s, and the Air Force is known to have some 653s in the inventory.
e stock was the vinyl acetate coated two position stock, which would be correct for the 653. By every indication, it looks almost stock 653 except for the 1/7 barrel. Either way these AF carbines are great little lightweight rifles!
And just for the fun of it!
~Augee