LBE Unlimited ARBNT308 Barrel Nut 4130 Steel Black Phosphate AR-10
https://www.tandktactical.com/shop/784682014370-lbe-unlimited-arbnt308-barrel-nut-4130-steel-black-phosphate-ar-10-24527
https://www.tandktactical.com/web/image/product.template/24527/image_1920?unique=b37142b
This 308 Barrel Nut is compatible with your AR-10 and has a black phosphate finish.
