Based on a customer request I had a run of FGC-9 barrels made. 4140 steel with a QPQ finish in 4.5" threaded, 4.5" unthreaded and 16" threaded for yout choice of pistol/NFA or rifle/non-NFA builds. You can pair these with customized AR-15 FCG packs and FGC-9 Hardware kits to get most of the critical non-3D printed components in one go.
Wojtekweaponry.com
Wojtekweaponry.com