The B5 Systems Sierra K Stock (brand part number SRK-1655) gives an AR-pattern carbine a compact, minimalist buttstock built for mil-spec tubes without unnecessary bulk. B5 Systems machines it from durable, long-lasting materials and finishes it in black, keeping the shell small and light for a build focused on maneuverability over storage or cheek-riser features. At 5.63" long, 1.5" wide, and 3.8" tall, it weighs just 6.6 oz, adding minimal mass to the rear of a carbine while still giving a solid, positive shoulder weld.

Key Specifications

• Sized as a compact, minimalist buttstock design.
• Built for mil-spec receiver extension tubes.
• Finished in black.
• Measures 5.63 inches long.
• Measures 1.5 inches wide.
• Stands 3.8 inches tall.
• Weighs just 6.6 oz, adding minimal mass to the rear of the rifle.

Frequently Asked Questions

What tube does this stock fit? Mil-spec receiver extension tubes.

How much does it weigh? 6.6 oz, keeping the rear of the build light.

Is this a full-size or compact stock? It’s B5’s compact Sierra K design, built for a minimal footprint.

Buy the B5 Systems Sierra K Stock – Black

Keep your build light and minimal without sacrificing a solid shoulder weld. Order it from our B5 Systems lineup, part of our AR braces/stocks selection, at our Lubbock, Texas gun shop for fast, direct shipping.