B5 Systems SRK-1660 Sierra K Extension Kit
Proprietary mounting system for Sierra K Buttstock featuring mil-spec 7075 aluminum receiver extension, heavy buffer, extra power spring, castle nut, and quick disconnect end plate. Made in USA.
B5 Systems Sierra K Receiver Extension Kit
The Sierra K Extension Kit represents a purpose-built mounting system designed specifically for the Sierra K Buttstock. This kit provides everything needed to properly install and secure your buttstock to your AR-15 platform rifle.
What's Included
- Receiver Extension: Reduced-length, mil-spec diameter 7075 aluminum construction with 5-position adjustment
- Heavy Buffer: Short 3.5 oz buffer for optimal cycling
- Extra Power Spring: Engineered to work seamlessly with the complete system
- Castle Nut: Mil-spec quality for secure assembly
- Quick Disconnect End Plate: Allows for rapid buttstock removal when needed
Quality and Construction
All components are manufactured to military specifications and finished to exacting standards. B5 Systems manufactures this kit in the United States, ensuring consistent quality and supporting domestic production.
Compatibility
This extension kit is the proprietary mounting system for the Sierra K Buttstock and is engineered to work as a complete system for optimal performance and reliability.
Features
- reduced-length 5-position receiver extension constructed of 7075 aluminum
- includes a short heavy buffer (3.5 oz), extra power spring, castle nut and qd end plate.
