Yes, the Ballistic Advantage OPMOD Modern Series 5.56 AR-15 Government Profile Barrel is machined from 4150 Chrome Moly Vanadium Steel and features a Chrome-Lined Bore and Chamber.
Modern series is qpq nitride. Classic series is chrome lined bore and chamber with a manganese phosphate outer finish.
No, modern series is not chrome lined. As far as I know only their classic series is chrome lined (w/ phosphate outer). This one is just QPQ