Building an AR pistol lower from scratch takes a handful of key parts, and this kit puts the essentials together in one listing. The SB Tactical SBA3 Pistol Brace Black Lower Build Kit bundles the SBA3 brace, a mil-spec buffer tube assembly, and a complete lower parts kit — all mil-spec, so everything drops into any standard AR-15 lower without hunting down three separate orders.
SB Tactical SBA3 Pistol Brace (SBA3X-01-SB) Black
The SBA3 has been the go-to AR pistol brace since 2019, adopted by over 100 firearm manufacturers, and runs on any mil-spec carbine receiver extension with five adjustable positions. At 6.75 oz, it keeps a slim profile with an integral ambidextrous QD sling socket built right into the body.
- 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
This is the 6-position carbine extension tube the SBA3 mounts to, machined from hard-coat anodized aluminum and built to mil-spec tolerances. It ships complete with the buffer, buffer spring, castle nut, and end plate, so the rear of your lower is fully covered in one order.
- 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
This lower parts kit covers every internal component your AR-15 lower needs to function, from the trigger group and safety selector to the magazine catch and takedown pin detents. All parts are mil-spec dimensioned and drop into any standard AR-15 lower without modification.
- 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
What’s Included
- SB Tactical SBA3 Pistol Brace — Black (SBA3X-01-SB)
- Mil-spec 6-position carbine buffer tube
- Carbine buffer and buffer spring
- Castle nut and end plate
- Complete mil-spec lower parts kit
