Hello all: I have a friend who is buying a M16a1 according to him what bothers me is the photos. I thought a M16a1 was a fixed carry handle early M16 variant this one has a removeable carry handle upper which I think is wrong 2. ALso, the serial is a 6 digit one .Seems very early 3. the receiver is marked AR-15 and M16a1 and its a little faded where a lot of lettering is gone 4. serial is 788,000 serial number which is pretty early anything you can give me input on this is appreciated serial is blotted out for privacy thanks Haris