Microbest AR15 5.56 C158 MPI All-Chrome Bolt Carrier Group, Premium

5 reviews Write a Review
MSRP: $199.99
You save $60.00
*Est. In Stock 12/15*
Microbest AR15 5.56 C158 MPI All-Chrome Bolt Carrier Group, Premium
Microbest AR15 5.56 C158 MPI All-Chrome Bolt Carrier Group, Premium
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***In Stock on 12/15***



The Ultimate Hard-Use 5.56 Bolt Carrier Group:

These aren't designed to be pretty. They're not meant to compete with the gorgeous museum-quality $200+ units that other well-respected manufacturers are putting out. But this is not just another component; built to exceed military specifications, our bolt carrier group is designed to be the hard-use always-performing heart of your AR-15. It just happens to look pretty darn good.


***These are All-Chrome Except for Phosphate Gas Key and Extractor***

-Phosphate Extractor

-Phosphate Gas Key

-Sprinco 5-coil Extractor Spring and Sprinco Ejector Spring

-OCKS Fasteners, Properly Staked

Microbest is one of the finest manufacturers of mil-spec bolt carrier groups for the military and small arms manufacturers. These are individually High Pressure Tested and then undergo a Magnetic Particle Inspection. We recommend degreasing and lubricating before installation. Ships in OEM packaging.


All-Chrome M-16 BCG, Phosphate Gas Key and Extractor

Mil Spec Carrier

  • 8620 Tool Steel
  • Full Auto M-16 cut

Mil-Spec Bolt

  • C158 Steel
  • Shot Peened
  • High Pressure Tested (HPT) 
  • Magnetic Particle Inspected (MPI)
  • Chrome Silicon Ejector Spring by Sprinco

Mil Spec Extractor - PHOSPHATE 

  • 4140 Steel
  • Chrome Silicon Extractor Spring by Sprinco
  • Black Extractor Insert

Mil Spec Gas Key - PHOSPHATE

  • 4130 Steel
  • Optimized Carrier Key Screws (OCKS) provided by Michiguns
  • Properly Staked

Weight: 11.6oz

Customer Reviews

5 reviews

  • 5

    Smooth reliable bcg

    Love this Microbest chrome bcg. So far I've run about 500 rds through it without a single issue (as it should be) Combine that with the look and ease of cleaning... you got a winner

  • 4

    Micro best BCG

    The only reason I'm giving it for STARS is because I haven't tried it yet but it looks fantastic

  • 5

    Microbest premium chrome bolt carrier group

    Recieved in a timely manner. Absolutely phenomenal condition. Flawless function. Especially appreciate the use of Springco extractor and ejection springs. The phosphate extractor works well without slippage. The utilization of OCKS carrier keys and exceptional staking are icing on the cake. Best deal out there. I don't care about oem markings, I do however, care about function and longevity. This checks both those boxes. I'll be back.

  • 5

    Microbest enhanced chrome bcg

    Great prices for great products! Quick shipping and my dog loves their treats! One of my favorite companies to order from!

  • 5

    Amazing Value, Superb Staking, Get it !

    This BCG is absolutely the best value on the market in my opinion, especially with free shipping and no sales tax outside of Texas. The chrome application is very nicely done. It is not as smooth as NP3 but it is more durable and far less expensive. Don't get me started on the staking, its a thing of beauty , it is perfect , SERIOUSLY. Better than my Centurion & BCM. The Cam-Pin fits nice and snug too. Better than my JP Enhanced bolt. As of this writing , the following info is not listed on this webpage: The gas key is sealed with Permatex/The Cam-Pin is made from 4340/The Extractor is made from heat treated 4140 which is almost nearly as good as 4340. If they add the cryogenically processed Sprinco Gas Rings it will be even more complete. But make no mistake, this thing as is , is in all likelihood best deal on the market , nothing comes close in my estimation . 140 bucs for a chromed Microbest with Sprinco springs and Ocks screws is just WILD . This is the way.

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