Toolcraft 6.5 Grendel / 6mm ARC Bolt Carrier Group | Nickel Boron

Toolcraft 6.5 Grendel / 6mm ARC Bolt Carrier Group | Nickel Boron

The Toolcraft 6.5 Grendel / 6mm ARC Bolt Carrier Group is a full-auto M16-profile BCG built for AR-15 rifles chambered in either 6.5 Grendel or 6mm ARC. This configuration combines a 9310 steel Type II bolt with an 8620 steel carrier and a Nickel Boron finish for smooth cycling, strong wear resistance, and easier cleanup.

The Type II bolt uses a .136-inch bolt face depth, the correct geometry for modern 6.5 Grendel and 6mm ARC barrel extensions. Toolcraft shot peens and Magnetic Particle Inspects the bolt for quality control, while a D2 tool steel extractor, Mil-Spec O-ring, and triple gas rings help support consistent extraction and gas sealing.

Nickel Boron is applied to both the bolt and carrier, creating a slick, low-friction surface that helps resist carbon adhesion and corrosion. The finish also makes routine maintenance easier compared with more traditional porous coatings while giving the BCG its distinctive silver appearance.

The full-mass M16 carrier preserves conventional AR-15 cycling characteristics and includes forward assist serrations. Toolcraft uses an 8620 steel cam pin and 416 stainless steel firing pin, while the gas key is secured with Grade 8 fasteners and properly staked for reliable use in direct-impingement systems.

Key Features

• Designed for 6.5 Grendel and 6mm ARC AR-15 platforms
• Type II .136-inch bolt face depth
• Full-auto M16 carrier profile
• 9310 steel bolt
• 8620 steel carrier
• Nickel Boron finish
• Shot-peened bolt
• Magnetic Particle Inspected (MPI)
• D2 tool steel extractor
• Mil-Spec extractor O-ring
• Triple gas rings
• Grade 8 gas key fasteners
• Properly staked gas key
• 8620 steel cam pin
• 416 stainless steel firing pin
• Forward assist serrations
• Standard AR-15 carrier dimensions
• Approximately 11.52 oz weight
• Made in the USA
• Backed by Toolcraft’s lifetime warranty

Type II .136-Inch Bolt

The 9310 steel bolt uses a .136-inch bolt face depth for compatibility with Type II 6.5 Grendel and 6mm ARC barrel extensions. This geometry is critical when matching the BCG to a compatible barrel and keeps both cartridges within the standard AR-15 carrier platform.

Nickel Boron Finish

The Nickel Boron treatment provides a smooth, low-friction surface that helps reduce drag during cycling while improving resistance to wear and corrosion. Its slick finish also makes carbon and fouling easier to remove during routine cleaning.

Full-Mass M16 Carrier

The 8620 steel carrier uses a full-auto M16 profile to maintain standard reciprocating mass and dependable cycling characteristics. Forward assist serrations, a properly staked gas key, and standard AR-15 geometry make it a straightforward fit for compatible direct-impingement builds.

Compatibility

• AR-15 rifles chambered in 6.5 Grendel using a Type II .136-inch bolt face
• AR-15 rifles chambered in 6mm ARC
• Standard AR-15 upper receivers
• Direct-impingement gas systems