HMB Bolt Carrier Group - Black Nitride (Made in USA)

HMB Bolt Carrier Group - Black Nitride (Made in USA)

HMB Bolt by HM Defense is made in the U.S.A. and the HMB is 100% compatible with Mil-Spec M16 & AR-15 BCGs and can be installed as a drop-in bolt replacement in any existing M16 or AR-15 rifle.  The HMB bolt eliminates the pass through cam pin hole and replaces it with a cam pin socket and tapered cam pin design. This new patented design eliminates the natural weak point of Mil-Spec bolts by significantly increasing the amount of metal (and strength) at the cam pin location. The ultra-hard and corrosion-resistant Black Nitride ensures this BCG's continued reliability and precision. Additional benefits of  the HMB design include the elimination of the cam pin hole staking, reduction in potential cam & firing pin contact and a smoother operation of the BCG.


  • M16 Style (Full Auto)
  • .223/5.56 Caliber
  • Mil-Spec
  • Precision Machined
  • Heat Treated Steel
  • HMB Bolt - 9310 steel
  • Cam-Pin 4340 Steel
  • 8620 Gas Carrier
  • Made in USA
  • Ultra Hard Black Nitride Finish
  • Fits: AR-15 / M16

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All orders ship out within 48 business hours

  • Product Code: BCG-N-HM#
  • Availability: In Stock

Tags: Made in USA, Black Nitride Finish, .223/5.56 Bolt Carrier