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BCM Bolt Carrier Group (MPI) – Auto BCG

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Prices are discounted until the end of: 12th May 2026</

Original price was: $170.00.Current price is: $153.84.

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  • polymer80
    p80
    pf940c
    p80 glock
    glock 19 80 lower
    pf940sc
    polymer 80 glock 19
SKU: Item-Rarebreedtriggerus-25

Description

The BCM Bolt Carrier Group (MPI) – Auto BCG ensures reliable cycling and durability in AR15, M16, and M4 platforms, making it a dependable upgrade for builders and enthusiasts.

What you get

  • Auto-compatible bolt carrier group for AR15, M16, and M4 platforms
  • Parkerized exterior with chrome-lined interior
  • Machined to USGI specifications
  • Proper Mil-Spec gas key, chrome-lined and heat-treated
  • Bolt assembly made from Carpenter No. 158® steel, shot-peened for strength
  • Tool steel extractor and ejector included
  • BCM Extractor Spring for enhanced reliability
  • High Pressure Tested (HPT) and Magnetic Particle Inspected (MPI)

Build and finish

The BCM Bolt Carrier Group (MPI) – Auto BCG is precision-machined to meet USGI specifications, ensuring compatibility and performance across a wide range of platforms. The exterior is parkerized for corrosion resistance, while the interior is chrome-lined to reduce friction and wear over time. This combination of finishes ensures longevity and smooth operation, even under harsh conditions.

The bolt assembly is constructed from Carpenter No. 158® steel, a material known for its strength and durability. It undergoes a shot-peening process to enhance its fatigue resistance, making it capable of withstanding high-stress environments. The extractor and ejector are made from tool steel, further bolstering the BCG’s reliability. The gas key is chrome-lined and heat-treated to GI specifications, ensuring optimal gas system performance. Grade 8 fasteners secure the gas key, which is properly staked to maintain a strong connection.

Compatible platforms

  • AR15 rifles
  • M16 platforms
  • M4 carbines

Installation notes

Installing the BCM Bolt Carrier Group is straightforward and requires no specialized tools. Simply remove your existing BCG and replace it with this unit, ensuring proper alignment with the gas tube and upper receiver. Always perform a function check after installation.

For those working on Polymer80 frame builds or modular pistol projects, this BCG offers a reliable, high-performance component that complements your custom setup. Its precision engineering and robust construction make it an excellent choice for builders seeking durability and consistency.

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Frequently Asked Questions about BCM Bolt Carrier Group (MPI) – Auto BCG

What does the BCM Bolt Carrier Group (MPI) – Auto BCG include?
The BCM Bolt Carrier Group (MPI) – Auto BCG comes complete with essential parts as described: The BCM Bolt Carrier Group (MPI) – Auto BCG ensures reliable cycling and durability in AR15, M16, and M4 platforms, making it a dependable upgrade for builders and enthusiasts. What you get Auto-compatible bolt carrier group for AR15, M16, and M4 platforms Parkerized exterior with chrome-lined interior Machined to USGI specifications Proper Mil-Spec gas key, chrome-lined and heat-treated Bolt assembly made from Carpenter No. 158® steel, shot-peened for strength Tool steel extractor and ejector included BCM Extractor Spring for enhanced reliability High Pressure Tested (HPT) and Magnetic Particle Inspected (MPI) Build and finish The BCM Bolt Carrier Group (MPI) – Auto BCG is precision-machined to meet USGI specifications, ensuring compatibility and performance across a wide range of platforms. The exterior is parkerized for corrosion resistance, while the interior is chrome-lined to reduce friction and wear over time. This combination of finishes ensures longevity and smooth operation, even under harsh conditions. The bolt assembly is constructed from Carpenter No. 158® steel, a material known for its strength and durability. It undergoes a shot-peening process to enhance its fatigue resistance, making it capable of withstanding high-stress environments. The extractor and ejector are made from tool steel, further bolstering the BCG's reliability. The gas key is chrome-lined and heat-treated to GI specifications, ensuring optimal gas system performance. Grade 8 fasteners secure the gas key, which is properly staked to maintain a strong connection. Compatible platforms AR15 rifles M16 platforms M4 carbines Installation notes Installing the BCM Bolt Carrier Group is straightforward and requires no specialized tools. Simply remove your existing BCG and replace it with this unit, ensuring proper alignment with the gas tube and upper receiver. Always perform a function check after installation. For those working on Polymer80 frame builds or modular pistol projects, this BCG offers a reliable, high-performance component that complements your custom setup. Its precision engineering and robust construction make it an excellent choice for builders seeking durability and consistency.
Do I need an FFL to purchase BCM Bolt Carrier Group (MPI) – Auto BCG?
No. This product is a part or accessory and does not require an FFL for purchase or shipping.
Is BCM Bolt Carrier Group (MPI) – Auto BCG legal in my state?
While BCM Bolt Carrier Group (MPI) – Auto BCG is legal in most states, always verify your local laws before placing an order. We comply with all state regulations.
Do Glock mags work with BCM Bolt Carrier Group (MPI) – Auto BCG?
In most cases, yes — Glock-compatible frames are designed to accept Glock OEM and compatible magazines. Always confirm fitment in the product details.
Can I conceal carry BCM Bolt Carrier Group (MPI) – Auto BCG once built?
That depends on your state’s concealed carry laws. Once properly serialized and registered, carrying may be allowed under state law.
How long does it take to receive BCM Bolt Carrier Group (MPI) – Auto BCG?
We ship all over the USA within 1–3 business days. You will receive tracking once shipped. Delivery times vary by carrier and region.

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