B5 SYSTEMS SIERRA K STOCK

The B5 Systems Sierra K Stock is a compact, purpose-built solution designed for PDW and short-barreled rifle platforms where space, weight, and maneuverability matter most. Engineered with a reduced footprint and streamlined profile, the Sierra K enhances handling without sacrificing durability or performance.

Featuring a slim ergonomic cheek weld, the Sierra K provides consistent and comfortable head positioning in a compact form factor. The snag-free, low-profile adjustment latch allows for smooth operation, while internal tensioners ensure a tight, rattle-free fit on the receiver extension.

Built from MIL-SPEC materials and finishes, the Sierra K is designed to withstand hard use in demanding environments. The stock includes ambidextrous fixed sling mounts and limited-rotation QD sling sockets, offering flexible sling attachment options for modern setups.

An anti-slip buttpad improves stability and recoil control, while the compact design makes it ideal for confined spaces, transport, and fast deployment scenarios.

The Sierra K mounts via a shortened compact MIL-SPEC receiver extension (required). When used on a standard carbine buffer tube, the stock will not fully collapse.

Available in multiple color options, the B5 Systems Sierra K Stock is the perfect upgrade for compact AR builds and PDW configurations.

Overview

The Sierra K is a purpose-driven compact stock, optimized for use on PDW and compact weapon systems. Features include reduced overall size and slim cheek profile, snag-free adjustment lever, limited rotation QD and integral fixed sling mounts, internal tensioners, and anti-slip buttpad. Mounts via shortened compact Mil-Spec receiver extension.

Features

• Optimized for PDW and Compact Weapon Systems
• Low-Profile Adjustment Latch
• Slim-Profile Ergonomic Cheek Weld
• Color-Matched Steel Hardware
• Ambidextrous Fixed Sling Mounts and Limited Rotation QD Mounts
• Mil-Spec Materials and Finishes
• Mounts via Sierra K Receiver Extension Kit
• Available in All Standard Colors

Specs

• Weight: 6.6 oz
• Length: 5.63 in
• Width: 1.5 in
• Height: 3.8 in