Luth-AR BS-10B Buffer Spring 223/5.56 AR-15 - A2 Rifle-Length

The Luth-AR BS-10B is a replacement 223/5.56mm buffer spring purpose-built for the AR-15 rifle platform equipped with an A2 rifle-length receiver extension.

Manufactured from stainless steel, this spring lives inside the AR-15 buffer tube and drives the buffer and bolt carrier group through their cycle during firing. Luth-AR calibrates the BS-10B specifically for 223 Remington and 5.56x45mm NATO chamberings, making it a drop-in fit for any standard rifle-length AR-15 lower. The spring stands 13-1/4" tall with 44 coils for reliable, repeatable cycling.

The BS-10B is the correct replacement spring for AR-15s running a fixed A2 buttstock on a rifle-length buffer tube, and is a worthwhile spare to keep on hand for routine rebuilds and field service.