What is the MK1-EB?  The MK1 lower receiver is the foundation for all of the firearms we produce, while EB is an abbreviation for Cerakote (E)lite, (B)lackstone. The MK1-EB line embraces individualistic design elements coupled with superior quality parts and components. Through the MK1-EB line we are attempting to scale the unscalable as no two MK1-EB firearms are exactly alike.  When you purchase a MK1-EB, you are purchasing a one of a kind product.  Do not be confused though, the MK1-EB is built to be a reliable tool that sees use, not a safe queen and we ask that you treat it as such. Please view below to learn more about the coatings previously mentioned.

The Elite series of Cerakote is superior to the traditional H Series in terms of hardness and abrasion resistance.  We use Cerakote Elite on EB lower receivers, upper receiver exteriors, and rails.

  • Exceeds 9h scratch and gouge hardness (ASTM D33630)
  • Taber abrasion greater than 8000 wear cycles per mil (ASTM D4060)
  • Corrosion resistance more than 3000 hours (ASTM B117)
  • Direct and indirect impact resistance of 160 in-lbs. (ASTM D2794)
  • 0mm coating loss at 180 mandrel bend (ASTM D522)
  • Coefficient of Friction rivaling Teflon at 0.11 (Steady-State Dynamic Coefficient of Friction Under Load)

Blackstone is a proprietary PTFE Teflon based coating that was developed by IA Coatings.  We use Blackstone on the interior of our EB upper receivers.

Blackstone exhibits extreme anti-friction properties.  With use, wearing surfaces become smoother, leading to smoother bolt cycling even when subjected to extended periods between cleaning.  Through its self-lubricating properties, cleaning is also made much easier.  Additionally, Blackstone consists of graphene, which significantly increases its durability and wear resistance. 

Our BCG Guarantee

We think our BCG’s are among the best there are!  To back this up, we provide a limited lifetime warranty for all of our BCG’s, whether purchased individually or in one of our firearms.