B5 Systems SOPMOD Sierra K Stock FDE - Collapsible Mil-Spec Buffer

The B5 Systems Sierra K Stock delivers enhanced stability and comfort for AR-15 platforms while maintaining the compact profile operators demand. This collapsible stock features B5's proven SOPMOD design with optimized cheek weld geometry and reduced length of pull for improved weapon manipulation in confined spaces.

What Makes This Different

Unlike standard M4 stocks, the Sierra K incorporates dual waterproof battery storage compartments and an enhanced rubber buttpad for superior recoil management. The stock's shortened length of pull reduces overall weapon length by 0.75 inches compared to standard SOPMOD stocks while maintaining full adjustability across six positions. B5's proprietary polymer construction provides 20% weight reduction over aluminum alternatives without sacrificing durability.

Key Features

• Dual waterproof battery storage compartments with secure latching system
• Enhanced rubber buttpad with anti-slip texture for improved shoulder contact
• Six-position collapsible design with secure mil-spec buffer tube compatibility
• Shortened length of pull reduces overall weapon length by 0.75 inches
• Flat Dark Earth finish matches military and law enforcement color schemes
• Ambidextrous QD sling swivel attachment points on both sides
• Reinforced polymer construction rated for 10,000+ cycle durability testing

Field testing demonstrates the Sierra K's reliability across temperature ranges from -40°F to 160°F without dimensional changes or function degradation. The stock performs consistently in law enforcement patrol rifles, competition shooting, and tactical training environments. The enhanced buttpad geometry distributes recoil forces across a larger surface area, reducing felt recoil by approximately 15% compared to standard hard plastic stocks.

Technical Specs

• Overall Length: 9.5 inches extended, 6.75 inches collapsed
• Weight: 8.2 ounces
• Material: Reinforced polymer construction
• Finish: Flat Dark Earth (FDE)
• Compatibility: Mil-spec buffer tubes (1.146" diameter)
• Battery Storage: Dual CR123A or AA compartments
• Sling Attachments: QD swivel compatible, 1.25" loop
• Country of Origin: Made in USA

The Sierra K represents B5 Systems' commitment to functional innovation without unnecessary complexity. Professional users choose this stock for its proven reliability record and practical feature set that enhances weapon performance rather than adding bulk.