Expo Arms 5.56 NATO Complete M16-Cut AR-15 Bolt Carrier Group - Nitride

Manufactured by Expo Arms
Manufactured by Expo Arms
18 Reviews

In Stock

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The Expo Arms 5.56 NATO Complete M16-Cut AR-15 Bolt Carrier Group is a reliable choice for any AR-15 build. This drop-in BCG features a MIL-SPEC dimension, magnetic particle inspected carpenter 158 steel bolt, and corrosion-resistant salt bath nitride finish. It is proudly made in the U.S.A. using domestically sourced 8620 steel. The M16 cut carrier comes with a properly staked grade 8 screws-fastened gas key. With its lifetime warranty, this BCG ensures long-lasting service.


  • 4140 steel cam pin
  • MIL-SPEC gas rings
  • Aircraft quality 8620 steel carrier
  • 8740 steel firing pin with hard chrome finish
  • Carpenter 158 steel bolt
  • Salt bath nitride finish
  • 4130 steel gas key
  • Magnetic particle inspected
  • MIL-SPEC O-ring
  • .233/5.56 NATO caliber

Upgrade your AR-15 with the Expo Arms 5.56 NATO Complete M16-Cut AR-15 Bolt Carrier Group and experience the reliable performance and durability it offers. Proudly made in the U.S.A., this BCG is designed to withstand the demands of your firearm for a lifetime of service.

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Bolt FinishSalt Bath Nitride
Bolt MaterialCarpenter 158 Steel
BrandExpo Arms
Caliber Gauge5.56 NATO
Carrier FinishSalt Bath Nitride
Carrier Material8620 Carpenter Steel
Carrier StyleM16 Bolt Carrier
High Pressure TestedHigh Pressure Tested
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

18 reviews

  • 3 stars
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  • 1 star
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Awsome sales experience and great product

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This item was an add on option to the Bear Creek Arsenal 16" Mlok 300 AAC Blackout upper assembly I purchased to add functionality to my home built 5.56mm AR. This is a melonited (Nitrided) BCG. After a day at the range, I came home and cleaned the upper. The melonite finish makes cleaning a very easy task. This BCG functioned flawlessly. I'm really impressed with the speed that Primary Arms had the upper with options delivered on my doorstep only 3 days after I ordered it.Great product at a great price. Thanks Primary Arms!

I'm happy.

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Will update if I have any issues but upon initial inspection this is a very nice BCG. Mine has absolutely no tool maks, the nitride is smooth and looks really nice. BCG is in spec compared to other BCG's I have. I'm happy with this purchase.


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Updating my review. I've had this for about 7 months as of 3/06/19. I have about 800 rounds cycled so far with this BCG and I have not had a single malfunction. This is paired with the Bear Creek 7.5 inch nitrided barrel. Again... the machining and finish are perfect. Been recommending this BCG to everyone. Unless you want something really fancy or gotta have a specific logo, I see no benefit in spending more on other brand names when you get the same quality for less.


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Everything you would expect from a $200 BCG for less than $100. Over 200 rounds on the first day and zero issues. Will update if it performs less than expected, but I don't foresee any issues.

Good bang for your buck


5k rounds and still strong. Had an extractor shatter but thats not an issue.

Great BCG


Amazing BCG for $100. Build quality is great and works flawlessly. Would definitely recommend this BCG to anyone.

Works Great


This is a steal. It works well and is perfect for both Wylde and Nato. Quick shipping as always!

Great value - works

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Functions just as you’d want it to, it’s a bolt carrier.
Having less than 100 rounds through the new rifle it’s too early to tell.

3-4000 rounds is when a BCG really starts to show it’s worth but so far, so good.

3 Years of use

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Bought in 2020 for $99 at the time, for the first AR I built. This BCG will do the job. I dropped it in a FN M16A4 upper. normal use I'd say I run 150-300 rounds in a day, in a fairly short period. After over 2,000 rounds the extractor gave up and the gas rings needed replacing. Not a surprise as they are common failure parts, hard use will wear them out eventually. After replacing it was ready to go, no other underlying issue. Great BCG if you're just starting out, or on a budget.

Quality product

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Found this to be on sale ..sure glad that it was very reasonably priced and the sale was just a bonus..great product recommendations for the person looking for good buying experience