RTB 10.5" 300 Blackout Upper Receiver - Black | A2 | 10" M-LOK | Without Bolt Carrier Group and Charging Handle
This 10.5 inch M-LOK upper receiver comes with our RTB 10 inch free float handguard and is built with only the best Mil-Spec components. The heart of this upper is comprised of a 4150 barrel making the action smooth and easy to keep clean.
| Barrel | Specifications |
|---|---|
| Caliber | 300BLK |
| Length | 10.5" |
| Material | 4150 Chrome Moly Vanadium |
| Profile | Medium |
| Finish | QPQ Corrosion Resistant |
| Gas System Length | Pistol |
| Gas Block Journal | .750" |
| Dimpled? | No |
| Twist Rate | 1:7 |
| Muzzle Thread | 5/8x24 TPI |
| Weight | 20.8oz |
| Barrel Extension | M4 Feed Ramps |
| Target Crown | 11 Degree |
Upper Receiver:
- Machined from a Mil-Spec 7075 T6 forging
- M4 Feed ramps
- Cerakoted in Tungsten
- Made in the U.S.A.
Handguard:
- MATERIAL: BLACK ANODIZED ALUMINUM HANDGUARD, ALUMINUM BARREL NUT
- PRECISION BORE
- ACCEPTS M-LOK RAIL SECTIONS & ACCESSORIES
- 7075-T6 BARREL NUT
- RAIL LENGTH IS MEASURED ALONG THE TOP
- INNER DIAMETER: 1.36"
Please Note: Uppers may present light fouling from our quality control process and/or test firing



