Otis' Chamber Brush has a brass Tufcor wire stem that is corrosive-resistant and has a tighter twist for better bristle retention. The tapered bronze bristles scrub the chamber, neck and shoulder, while the steel bristles at the base scrub the star chamber of the locking lugs. It also has a standard 8-32 thread.
This brush is for 5.56mm cal rifles.
Determined at checkout.