Josh, this has come up recently, and I'd like to get your input - if it's at all possible. If there are discolsure issues that would arise from stating any of this information, then I (we) understand, and that would be a perfectly acceptable answer...
Seems like the new Fulton Armory barrels are using Armalite gas tubes. This would require a manufacturing change, to accomodate those longer gas tubes. Did that happen, and everything from Fulton is now using the longer Armalite gas tubes? (The .308s, only, it seems - everything else is TDP-spec'd on the AR15s). See below quotes:
Any light you could shed on this would defeinitely help answer questions - but don't get into trouble with Clint! :))