Bolts & Bolt Carrier Groups

The Grendel Hunter AR-15 BCG: Precision-Tuned Reliability

BCG Technical Specifications:

    • Calibers: 6.5 Grendel/6mm ARC/.22 ARC | .450 Bushmaster/.458 SOCOM | .223 Remington/5.56 NATO

    • Carrier: M16 Auto Profile (8620 Steel) for smooth cycling and increased mass.

    • Gas Key: 4130 Steel with properly staked Grade 8 fasteners.

    • Bolt: 9310 Steel

    • Small Parts: 4140 Steel Cam Pin and Hard Chrome Firing Pin.

Professional Grade Finishes

We offer four distinct finishes, each offering a significant upgrade over the old Mil-Spec phosphate in terms of lubricity, hardness, and ease of cleaning.

 

Black Nitride

  • Surface Hardness: ~740 HV (Vickers)
  • The Process: A salt-bath thermo-chemical treatment that hardens the steel.
  • The Benefit: Far more durable and smoother than original Mil-Spec magnesium phosphate with excellent corrosion resistance.

Nickel Boron (NiB)

  • Surface Hardness: ~1800 HV (Vickers)
  • The Process: UCT EXO® (High Boron content).
  • The Benefit: An extremely hard, durable finish with a very low friction coefficient. It’s smooth and wipes clean easily.

DLC (Diamond-Like Carbon)

  • Surface Hardness: ~2300 HV (Vickers)
  • The Process: Next-level Plasma Enhanced Chemical Vapor Deposition (PECVD)
  • The Benefit: High hardness, Excellent abrasive wear resistance, Low thermal conductivity, Ultra-Low friction level.

P51+ High Polish Black

  • Surface Hardness: ~2300 HV (Vickers)
  • The Benefit: The same attributes of our DLC, but it receives extra polishing cycles to give it an EXTREMELY smooth and deep, black finish.

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Josh M
Absolutely love the finish...top notch. I would definitely buy again without hesitation.
Mark
This is an awesome bolt carrier group. Super smooth functionality and super easy to clean. THE BEST!!!!!
Bobby
Excellent delivery time, product as advertised! Great upgrade to my build. Definitely has resolved my issues in running a suppressed gun. Will recommend to others!