Get the B5 Systems B5 Extention Kit Black from Nautilus Arms.
The Sierra K Receiver Extension Kit is the proprietary mounting system for the Sierra K Buttstock. It consists of a reduced-length, mil-spec diameter, 7075 aluminum, 5-position receiver extension, a short heavy buffer (3.5 oz), extra power spring, castle nut, and quick disconnect end plate.
Specifications
| Brand | B5 Systems |
|---|---|
| Model | Sierra K |
| Color | Black |
| Type | Buffer Tube Complete Assembly |
| MPN | SRK1660 |
| UPC | 814927024793 |
