MRA Nitride AR-15 Bolt and Barrel 7.62×39


Out of stock

Maple Ridge Armoury Nitride barrels are precision CNC machined from premium, 4140 CMV steel blanks to provide us with the absolute best possible foundation from which to machine and assemble all Maple Ridge Armoury barrels.



Maple Ridge Armoury  Nitride AR-15 barrels are precision CNC machined from premium,  4140 CMV steel blanks.  Following bore drilling, the blank is button cut with precise 6 grove rifling and completely stress relieved.  During the final inspection, the blanks are air gauge measured to ensure exacting tolerances.  These steps ensure we have the absolute best possible blanks from which to machine our barrels.

All MRA AR-15 barrels have precision cut chambers, gas ports, and an 11 – degree target crown .  We use an SPR profile to achieve an optimal balance between harmonic resistance , heat resistance, and weight savings.   The 1/9.5” twist rate will effectively stabilize standard 7.62×39 projectiles including 123gr surplus.
All Maple Ridge Armoury Nitride AR-15 barrels undergo QPQ Black Nitride heat treatment. This heat treatment provides superior corrosion, wear, and abrasion resistance while offering the greatest accuracy potential of any barrel heat treating process.  Instead of adding material to the bore (like Chrome lining), Nitride treats the existing steel by imbuing nitrogen into the steel itself.  This is done through a liquid salt – bath where the added element greatly hardens the steel a few thousand this into the material.  As a treatment, Nitride does not add any materials to the bore, rather it treats the bore as it came from the factory .  Nitride treats both the inside and the outside of the barrel and does not require any oils to provide corrosion protection.
  • Material: 4140 CMV Steel
  • Treatment: QPQ Black Nitride
  • 7.62×39 – 1/9.5” twist rate
  • 11 degree target crown
  • Precision cut chamber and gas port
  • M4 Barrel Extension
  • Gas Journal: .750″
  • Barrel Length and gas system:
    • 18.6″ carbine
    • 14.5″ carbine
    • 10.5″ pistol
  • Weight:
    • 18.6″ SPR – 2lb 2oz
    • 14.5″ SPR – 1lb 10oz
    • 10.5″ SPR – 1lb 4oz
  • Lifetime warranty
  • Made in Canada


The Maple Ridge Armoury AR-15 Nitride Bolt Assembly is a precision machined, US MilSpec bolt for the AR-15, M16, M4 series semi-automatic firearm.  All bolts are ground after heat treatment and then MPI tested as part of our strict quality control.  This bolt is black nitride treated providing excellent corrosion resistance, wear resistance, hardness , and lubricity.  The bolt face is chamfered to assist with engagement with the cartridge and along with the rubber extractor insert assist in ejection of the spent case.

  • Caliber: 7.62×39
  • Material: 9310 Steel
  • Treatment:  Black Nitride
  • Ground after heat treat
  • MPI tested
  • Chamfered bolt face
  • Rubber insert inside extractor spring


Additional information

Weight 1 kg
Dimensions 51 × 5 × 5 cm
Barrel Length

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Anodized Black




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