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MPI Nickel Boron AR-15 BCG — M16 Cut | .223/5.56

Regular Price: $159.99
Member's Price: $152.00
Members Save 5% ($7.99)
MPI Nickel Boron AR-15 BCG — M16 Cut | .223/5.56
Regular Price: $159.99
Member's Price: $152.00
Members Save 5% ($7.99)
In stock (47)

Overview

A fully MIL-SPEC Nickel Boron coated AR-15 Bolt Carrier Group built to run hard, clean easy, and last. M16 cut carrier, Carpenter 158 steel bolt, magnetic particle inspected — everything correct, nothing cut short. 100% USA made.

FRT Compatible: M16 cut carrier is required for reliable function with the Partisan Disruptor FRT. This BCG meets that requirement. If you're building an FRT platform, see our Disruptor + HFRT Buffer Bundle — or add this BCG to complete the setup.

Specifications

Caliber .223 Remington / 5.56 NATO
Finish Nickel Boron
Carrier Cut M16 Cut
Carrier Material 9310 Steel
Bolt Material Carpenter 158 Steel
Extractor & Ejector 4140 Steel — Nitride Coated
Cam Pin 4140 Steel
Firing Pin 8740 Steel — Hard Chrome Finish
Gas Rings MIL-SPEC
O-Ring MIL-SPEC
Inspection Magnetic Particle Inspected (MPI)
Origin 100% USA Made
Price $159.99

Features

  • Nickel boron finish — harder, slicker, and easier to clean than phosphate or standard nitride
  • M16 cut carrier — required for FRT builds; compatible with all standard AR-15 platforms
  • Carpenter 158 steel bolt — MIL-SPEC standard, same spec used by military contractors
  • 9310 steel carrier — high-strength alloy with excellent fatigue resistance
  • 4140 steel extractor & ejector with nitride coating — added hardness and corrosion resistance
  • 4140 steel cam pin — matched hardness to carrier for long service life
  • 8740 steel firing pin with hard chrome finish — corrosion resistant, dimensionally stable
  • MIL-SPEC O-ring and gas rings — correct sealing and gas management from day one
  • Magnetic particle inspected — every bolt individually tested for surface and subsurface defects
  • 100% USA made

Why Nickel Boron?

Nickel boron is harder and has a lower coefficient of friction than phosphate. That means less heat buildup, less fouling adhesion, and a BCG that wipes clean in seconds rather than minutes. It runs reliably with or without lubrication — important for high-rate-of-fire applications like FRT builds where the BCG cycles under greater stress and frequency than standard semi-auto use.

Combined with an M16 profile carrier and fully MIL-SPEC internals, this BCG is one of the most capable drop-in upgrades available for any mil-spec AR-15 platform.

FRT Compatibility

The Partisan Disruptor FRT requires an M16-profile BCG for reliable reset function. The M16 carrier tail provides the extended geometry that engages the Disruptor's reset lobe during the cycling stroke. A standard semi-auto carrier will not provide consistent reset. This BCG meets that requirement and is a direct recommended pairing for any Disruptor build.

Related Products & Resources

FRT Resources