A*B Arms Pro 5.56 NATO Bolt Carrier Group - Nickel Boron

Manufactured by A*B Arms
Manufactured by A*B Arms
3 Reviews
$159.99 $219.99

In Stock

Standard orders will ship out in 1 business day (M-F) if ordered by 3:30 pm CST. FFL orders will ship within 5 business days or less as long as we have the information for the transfer destination. NFA items will take longer to ship and are dependent upon ATF processing times.

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A*B Arms is built stronger because sometimes, lives are on the line. Their products stand up to the rigors of combat, police and private security operations, where failure is not an option.

The A*B Pro 5.56 Bolt Carrier Group is a MIL-SPEC drop-in ready component for the AR-15/M4 platform. The nickel boron finish offers dry lubrication for treated parts. The carrier, bolt, and cam pin require virtually no lube during use. The extractor has a surface finish providing superior extraction during firing. Crafted using high-end Swiss machinery for tight tolerances and finish.

  • Bolt
  • Carpenter 158 steel
  • Heat treated
  • Shot peened
  • Magnetic particle tested
  • Nickel boron coated
  • Bolt carrier
  • 8620 steel
  • Nickel boron coated
  • Nickel boron coated bore
  • M16 cut
  • Gas key
  • 4130 steel
  • Nickel boron coated
  • Properly staked 4140 steel gas key screws
  • Cam pin
  • 4340 steel
  • Heat treated
  • Nickel boron coated
  • Extractor
  • Aircraft quality E4140 steel
  • Heat treated
  • Shot peened
  • Nickel boron coated
  • Firing pin
  • AISI 8740 steel
  • Chrome coated
See More


Bolt FinishNickel Boron
Bolt MaterialCarpenter 158 Steel
BrandA*B Arms
Caliber Gauge5.56 NATO
Carrier FinishNickel Boron
Carrier Material8620 Carpenter Steel
Carrier StyleM16 Bolt Carrier
High Pressure TestedUntested
Magnetic Particle InspectMagnetic Particle Inspected
California Prop 65 warning

 WARNING: This product can expose you to chemicals, which are known to the State of California to cause Cancer and Reproductive Harm. For more information go to www.P65Warnings.ca.gov.

Ratings & Reviews

3 reviews

  • 3 stars
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  • 2 stars
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  • 1 star
  • 0 reviews

Great product... Buy it...


This BCG is great..... While I did not buy it here, Got it local from A*B Arms, it is good quality.... Nice staking on gas key, finish is still beautiful after a few thousand rounds, gas rings still doing their job well. The bolt itself is showing some discoloration but cleans up fine... If I were building another rifle I would be getting another one today.. You can keep your Fail Zero and your BCM's and your other "name brand" BCG's if you want. Shoot it, clean it, shoot it again and repeat..... A*B Arms... Veteran owned, Central Pennsylvania local....

Buy with confidence

by -

High end quality without the high end price. Functions flawlessly and has even finish. Would not hesitate to buy again. Have over a dozen different BCG’s and this one is near the top. Buy with confidence

High Pressure Testing


My only deterrent for purchasing this BCG is that for the amount of money that you're spending it should be high pressure tested.