Dirty Bird SBA4 Lower Build Kit

The Dirty Bird Industries SBA4 Lower Build Kit includes everything needed to finish your AR Pistol Lower Receiver using the ever popular SB Tactical SBA4 Stabilizing Brace. This kit includes the Dirty Bird enhanced Lower Parts Kit which features our 5-star rated Nickel Teflon Single Stage Trigger Group. This trigger features honed and polished engagement surfaces, a slick and durable Nickel Teflon finish and finely tuned trigger / hammer spring rates. This means you get a smooth trigger pull with very little take-up and a crisp clean break at 5 – 5.5 pounds. Additionally you’ll get an enhanced polymer trigger guard and an extra takedown / pivot pin detent and spring in case one gets lost during installation. The kit also includes the Dirty Bird AR-15 True Mil-Spec Carbine Receiver Extension / Buffer Kit. This popular buffer kit features a true Mil-Spec 6-Position Receiver Extension (buffer tube) machined from American Made 7075-T6 Aluminum, 3oz Carbine Recoil Buffer w/ steel counter weights, a chrome silicon buffer spring, hardened castle nut with staking cuts and mil-spec end plate.

Because there are so many grip options on the market and shooters are so different in their preferences, we’ve opted to simply include an A2 pistol grip as a part of the kit. This gives you something that is perfectly functional but doesn’t really add to the cost of the kit and enables you to choose whatever grip you’d like for your build.

Each component in this kit, down to the springs and detents are sourced from the best of the best and they’re all 100% American Made.

Includes:

SB Tactical SBA4 Pistol Stabilizing Brace

Dirty Bird AR-15 True Mil-Spec Carbine Receiver Extension / Buffer Kit

7075-T6 Aluminum 6-Position Mil-Spec Receiver Extension (7075-T6 Aluminum is nearly twice as strong as 6061)
3oz Carbine Recoil Buffer w/ Steel Counter Weights
Hardened Castle Nut w/ Staking Cuts
Mil-Spec End Plate

Dirty Bird Enhanced Lower Parts kit

Nickel Teflon Trigger Group
– Nickel Teflon Honed and Polished Trigger and Hammer
– Enhanced Disconnector
– Disconnector Spring
– Trigger Spring
– Hammer Spring
– Trigger / Hammer Pins (x2)Bolt Catch

Kaw Valley Precision Reduced Power Springs

Magazine Catch
Magazine Catch Button
Safety Selector
Enhanced Polymer Trigger Guard (w/ set screw)
Trigger / Hammer Pins (x2)
Takedown Pin
Pivot Pin
Takedown / Pivot Pin Springs (x3)
Takedown / Pivot Pin Detents (x3)
Safety Selector Detent
Safety Selector Detent Spring
Magazine Catch Spring
Trigger Guard Roll Pin
Bolt Catch Detent
Bolt Catch Detent Spring
Bolt Catch Roll Pin
Buffer Retainer / Detent
Buffer Retainer / Detent Spring
A2 Pistol Grip Assembly