Building an AR pistol lower from scratch takes a few key parts. This kit puts the main ones together in one listing. The SB Tactical SBA3 Pistol Brace Black lower build kit includes the SB Tactical SBA3 Pistol Brace Black, a mil-spec buffer tube assembly, and a complete lower parts kit. Furthermore, everything here meets mil-spec standards. Therefore, you can drop these into any standard AR-15 lower without hunting down three separate orders.

SB Tactical SBA3 Pistol Brace Black Lower Build Kit Overview

The SB Tactical SBA3 Pistol Brace Black has been the industry standard for AR pistol builds since 2019. Over 100 manufacturers have used it. In addition, it runs on mil-spec carbine receiver extensions and adjusts to five positions. The black finish keeps your build clean and consistent. Moreover, the slim profile doesn’t add unnecessary bulk or width.

At 6.75 oz, it won’t change the handling feel of your pistol build. Specifically, the integral ambidextrous QD sling socket works on either side without extra hardware. Therefore, you get a fully functional brace with no extra steps. As a result, the SBA3 Black is one of the most practical and widely adopted AR pistol brace options available. This brace is designed and made in the USA.

• Model: SBA3X-01-SB
• Color: Black
• Weight: 6.75 oz
• Brace type: Collapsible, 5-position adjustable
• Length collapsed: 6.1″
• Length extended: 9.5″
• Width: 1.8″
• Material: Synthetic polymer
• Sling socket: Integral ambidextrous QD
• Compatible with: Mil-spec carbine receiver extensions
• Made in the USA

Mil-Spec Buffer Tube Assembly

The mil-spec buffer tube assembly in this kit is what the SBA3 Black mounts to. It’s a 6-position carbine extension tube. In addition, the buffer, buffer spring, castle nut, and end plate are all included. Therefore, the rear of your lower is fully covered in one order. The tube is machined from aluminum and hard-coat anodized for durability. Moreover, every component in the buffer tube assembly meets mil-spec tolerances, so the SBA3 Black slides and locks into position without fitment issues. Consequently, you can complete your lower build with confidence.

• Extension tube: 6-position carbine, mil-spec
• Includes: Buffer, buffer spring, castle nut, end plate
• Material: Aluminum, hard-coat anodized
• Standard: Mil-spec dimensions

Complete Lower Parts Kit

The lower parts kit covers all the internal components your AR-15 lower needs to function. It includes the trigger group, hammer, disconnector, safety selector, pistol grip hardware, magazine catch, bolt catch, and the associated springs and pins. In addition, every part meets mil-spec dimensions. Therefore, these parts drop into any standard AR-15 lower without modification. As a result, the SB Tactical SBA3 Pistol Brace Black lower build kit gives you everything you need to go from a stripped lower to a complete, functional lower assembly in one package. Moreover, sourcing each of these parts separately would take significantly more time and effort.

• Includes: Trigger, hammer, disconnector, safety selector, pistol grip screw and lock washer
• Includes: Trigger guard, trigger guard roll pin, magazine catch, magazine catch spring, magazine button
• Includes: Bolt catch, bolt catch spring, bolt catch roll pin, bolt catch plunger
• Includes: Buffer retainer and spring, takedown pin detents and springs, pivot pin detents and springs
• Standard: Mil-spec dimensions
• Compatible with: Standard AR-15 lower receivers