RADIAN ENHANCED BCG AR15 223/556 BLK NIT BLEMThe Radian Enhanced Bolt Carrier Group Blem for AR15 in . 223 5. 56 with Black Nitride finish offers the same exceptional performance as the standard version, but at a reduced price due to minor cosmetic imperfections. This BCG features a case hardened 9310 steel bolt and 8620 steel carrier, both treated with a self lubricating black nitride finish. Engineered to minimize carrier tilt and reduce friction, this blemished BCG maintains the same high