bought this today:

POF piston-driven upper set up for 3-gun competition. Upper has a Mike Rock, 18" 5R fluted barrel with a 1/8 twist. Predator rail free float tube that has been milled on the back end to allow mounting of Leupold CQT or an ACOG directly to the upper receiver. The front end has been milled around the gas block to completely free float the barrel.

Upper comes with hard chromed bolt and bolt carrier and has the inside of the upper receiver and charging handle coated with POF's proprietary, friction reducing coating. Heat sink barrel nut helps keep the chamber and handguards cool during rapid fire stages. Charging handle comes with Badger Ordnance extended latch.