The Chiappa MFour Gen II Rimfire AR-15 Upper Reciever Assembly features a parkerized steel, heavy profile, match barrel. The receiver itself is made from a reinforced, improved polymer that is very similar to aluminum. The polymer receiver provides a strong but extremely lightweight housing for the steel bolt.
The Chiappa MFour Gen II Rimfire AR-15 Upper is economical, reliable, and an excellent choice for introducing young shooters and keeping skills sharp at a lower cost than training with .223/5.56 ammunition. This upper fits any Mil-Spec lower receiver and requires no permanent modification to the host firearm.
- Upper Receiver Type: Modified A3 Flat-Top
- Barrel Length: 18.5"
- Barrel Contour: Heavy
- Barrel Material: Chrome Moly Steel
- Muzzle Thread Pattern: 1/2"-28
- Chrome Lined: No
- Barrel Finish: Parkerized
- Twist Rate: 1 in 16"
- Chamber: 22 Long Rifle
- M4 Feed Ramps: No
- Muzzle Device: Muzzle Brake
- Gas System Length: None, Blowback
- Gas Block Diameter: N/A
- Handguard: 7.8" Free Float Quad Rail
- Sights: None
- Bolt Carrier Assembly Included: Yes
- Bolt Carrier Type: 22 LR Compatible Carrier
- Includes 2 28-Round Magazines