About the BCM® KD4 Spec Complete Upper Receiver w/ KMR-A13
KD4 Upper Group with twist rate designed for 77 grain Black Hills ammunition. This Upper Group features BCM® SS410 16″ Mid Length Upper Receiver Group w/ BCM® KMR *ALPHA* 13″ Handguard, 1/7.7 Twist DLC Finish on barrel.
DLC Coating stands for diamond-lkike carbon coating, and is a nanocomposite coating that has unique properties of natural diamond low friction, high hardness, and high corrosion resistance.
“Black Hills Ammunition has been making the most accurate and lethal 5.56 cartridges for years. In particular, their 77 grain OTM or MK 262 variants as its known in the military has performed without fail for over 20 years. I have used it myself and consider it lifesaving equipment.
