M4E1 Enhanced Upper, barrel wrench tool, and 9" MLOK rail.
You don’t need to time the barrel nut since the rail attaches directly to the receiver.
$110 shipped.
This Upper Receiver:
https://www.aeroprecisionusa.com/ar15-m4e1-enhanced-upper-receiver
This Rail:
https://www.aeroprecisionusa.com/ar15-quantum-mlok-handguards
