CMMG’s Endeavor 300 Mk4 line of upper receiver groups are designed for superior long-range accuracy. The Endeavor line features a 20-inch barrel so that you can easily pair the upper receiver with your existing AR15 lower and squeeze out every drop of ballistic performance.
- Hard Coat Anodized Receiver and Hand Guard
- CHARGING HANDLE: CMMG Oversized Ambi
- SLR Adjustable Gas Block
- RECEIVER: Forged 7075-T6 AL M4 type upper