Proprietary Mounting System for Sierra K Buttstock
The B5 Systems Sierra K Receiver Extension Kit delivers premium build quality for your compact firearm platform. Specifically engineered to work with the B5 Systems Sierra K buttstock, this kit provides all necessary components for proper installation and optimal performance.
Highlights
- Purpose-built for B5 Systems Sierra K buttstock compatibility
- Reduced-length design for compact weapon builds
- Complete kit includes all mounting hardware
- Mil-spec materials and construction
- 100% Made in USA
The Sierra K Receiver Extension Kit features a reduced-length, mil-spec diameter receiver extension machined from 7075 aluminum with 5 adjustment positions. The proprietary system includes a specialized short heavy buffer (3.5 oz) paired with an extra power spring to ensure reliable cycling in compact configurations. The included castle nut and quick disconnect end plate complete this premium assembly system.
Specifications
| Component | Material/Details |
|---|---|
| Receiver Extension | 7075 Aluminum, Mil-Spec Diameter, 5-Position |
| Buffer | Short Heavy Buffer (3.5 oz) |
| Spring | Extra Power |
| Castle Nut | Mil-Spec |
| End Plate | Quick Disconnect |
| Compatibility | Designed for B5 Systems Sierra K Buttstock |
| Origin | Made in USA |
Note: While designed specifically for the B5 Systems Sierra K buttstock, this kit may work with other stocks on the market. However, B5 Systems cannot guarantee proper function with non-Sierra K buttstock products due to its proprietary design specifications.
