buffer weight issue

[Tex Nomex]

Remember this for future builds: It's got nothing to do with the carbine buffer tube or carbine buffer. It is the long rifle gas system in a shorter-than-rifle barrel. It seems to need a larger gas port.

Try a different non-adjustable gas block.
-or-
Drill out the gas port. Easy with a drill press or for a shop to do.
-or-
Run a suppressor.
-or-
Try a Krink-style muzzle device.

You give up too easily. I truly believe this rig would be buttery smooth and accurate with a little more gas. Have you contacted BA and asked them how to make their barrel work? Could be out of spec.