Originally Posted by DrewH
I have owned both models. My understanding is the last batch of MT6400s came with a M16 bolt carrier. The switchover was Colt wide, older 6920s didn't have the M16 carriers, IIRC. I didn't think Colt made the Match Target series any more, are they still producing 6400s?
The difference is the rollmarks, pinned muzzle brake versus threaded on flashhider, fixed faux collapsible stock versus real collapsible, bayonet lug missing on the 6400.
I'd get the 6920 unless you are legally bound to get 6400, or it costs enough less that de-bannifying it would be less than getting a 6920. They do have "M4 Carbine" rollmarks, which are kind of cool, but I didn't like the "Match Target".