Why anyone buys these when you can pick up a Caracal 816a2 upper for $1250/800 (pro/.mil) is beyond me.
https://caracalusa.com/product/car816-a2-11-5-complete-upper/
MLOK handguard, 1/2x28 threaded barrel, adjustable gas, and Made in USA in Idaho.
The "B&T" is just a rebadged Caracal...