M16a2 clone-ish build barrel

[RobertTaylor]

Just picked up an a2 upper reciever, my understanding is that most of the newer barrels with an FSB already pinned on are for flat top recievers. Looks like they are a lightly different heights than ones used with a fixed carry handle reciever (if that makes sense)

Anyone know of a barrel that will work, or have a barrel that's not shot out? Either 14.5", 14.7", or 20"

 

[Anangrypasta]

So I actually built a 14.9 inch mid length F marked AR using an A2 upper. The F and A2 FSBs are different heights, and I believe the F marked FSB are higher, but there is enough adjustment space that you can drop the sight post low enough.

A2 uppers are my favorite. I built a What Would Stoner Do lightweight carbine using an old Colt M16A2 parts kit upper that was imported by Century as a C15. Pulled all the bad parts off, threw on a F marked BA 14.9 pencil with a welded A2, and all together only weighs 5 lbs.