From what I believe this maybe the 2nd or 3rd XM
carbine in the series I also believe this is the last
carbine before they devloped the more advanced M4
Carbine. The only difference I can tell is the XM177E2
has a shorter barrel than the M4.
The XM177E2 can be found in the movies Black Hawk
Down, and Heat which is so far the only movies I've
seen them in.
