OK, this is to settle a gunshop dispute that started today: The old Air Farce GAU-5A/A version of the vietnam M16, is it the exact same as the Army's CAR-15 just no forward assist (my position) or is it an entirely different animal (opposition)? Any pics would help a lot.
Thanks.

If you mean the Air Force's version of the XM177-series weapons?

Then yes, they were identical except for the lack of a forward assist on the upper.

The Air Force decided it didn't need them...(probably they thought of it as an added frill or cost they didn't need...)

At least, that's my understanding.

Ed

That's what I was trying to tell him...

The other gentleman who was speaking with me claimed the GAU-5 A/A did not have the forward assist (agreed with me on that) but he said it also did not have the semi-suppressor flash hider like the XM177E2 had and it had as he said "different guts". This gentleman also claimed that he saw these guns in the hands of not only the Air Police but the Marines as well.

You are, of course, correct.  If you need it I can try to dig out my copy of The Black Rifle or the Small Arms Review issues relating to the M16 ID.  Guts are the same.  I think that the USAF has rebuilt some of these guns.  As a result, they may (but probalby don't) have the A2 selectors and burst fire.  

Marines are wonderfully adaptive and resourceful.  Some Marines may well have had GAU-5 in VietNam or later.  That, however, is more likely to be because of some fancy trading then USMC issue.  In addition, the original XM-177 did not have, I think, the forward assist.  Marines were even more likely to trade for Army weapons than rarer USAF weapons.  Does your opponent not know that or was he so close that he was reading the model designation off the side?

Thanks for the backup. The gentleman I was debating with (IMHO) had a few things wrong with just about all the stuff he was saying.

As for the XM177, I thought that the E1 (prototype) had the shortened barrel of 10 1/2 inches and no forward assist but the field model of XM177E2 had the longer barrel of 11 1/2 inches with the semi-suppressor flash hider and the FA.