Rainier Arms Mountain - Stripped Upper Receiver Group CHF Barrel

Our Rainier Arms Mountain Series upper receiver group was designed for the enthusiast that's looking for a solid foundation for their next upper build using our 1:7 twist Mountain series barrel, our Mil-Spec upper receiver group and Lo Profile gas block. The rest is entirely up to the customer and can be easily built out.

Barrel Specs:

• Barrel Material: Chrome Moly Vanadium Steel
• Made of Mil Spec M249 Machine Gun barrel steel, with heavy M249 Chrome Lining, (appx. 2 times as thick as an M4 or M16)
• Barrel Type: Cold Hammer Forged
• Barrel Caliber: 5.56mm NATO Barrel
• Barrel Length: 14.5 Mid Gas, 16 Mid Gas, or 18 Rifle Gas
• Barrel Profile: Modified Mid Weight Government Profile
• Twist Rate: 1:7
• Muzzle Thread: 1/2A~—28 TPI (Threads Per Inch)
• Diameter At Gas Block: .750
• Bore: Chrome Lined
• Chamber: 5.56mm NATO

Does NOT come with a BCG, Muzzle device, Charging handle or handguard.

Component List:

• Rainier Arms Mountain Mid Weight Series 1:7 Twist
• Rainier Arms Match Lo Pro gas block
• Rainier Arms Forged Mil-spec Upper Receiver with UPK
• Rainier Arms Barrel nut
• Gas tube
• Weight: 18" - 2lbs 8.7 oz
• Weight: 16" - 2lbs 6  oz