Rainier Arms, Precision Match Grade Bolt Carrier Group, Black Nitride, 5.56mm

The Rainier Arms Precision Match Grade Phosphate BCG - 5.56 Nitride is machined and finished to a higher standard to meet and exceed all Mil Spec. It is machined using the most precise equipment in the industry. The bolts are MPI/HP tested & Marked to give you ultimate confidence in your weapon system.

Carrier

• Full Auto Carrier
• SAE 8620
• Heat Treated
• Nitride

Bolt

• 5.56/.223
• Carpenter 158 Steel
• Shot Peened
• Heat Treated
• Nitride

Extractor

• Machined from bar
• Shot Peened
• Heat Treated
• Maganese Phosphate
• Nitride

Extractor Spring

• Chrome Silicone for Longer Life
• Black Insert as per current Mil-Spec
• "O" Ring is high temp resistant dark brown

Extractor Retaining Pin

• Precision Machined
• Precision ground to diameter
• Precision ground to length
• Heat Treated

Firing Pin

• Machined and then precision ground for accuracy
• Heat Treated

Gas Key Bolt

• Precision manufactured in house with extra deep knurling
• Grade 8
• 1200 degree locking patch is factory applied to threads to help insure long lasting tightness

Gas Key

• Hard Chrome lined gas tube as per Mil-Spec
• Bolts installed to proper torque
• Staking on both sides of both bolts
• Nitride

Cam Pin

• Precision machined
• Heat Treated
• Nitride

Firing Pin Retaining Pin

• Precision bent
• Precision cut to length
• Heat Treated

Gas Rings

• Stainless Steel per Mil-Spec

Ejector

• Precision machined
• Heat Treated

Ejector Spring

• Chrome Silicone
• Precision ground ends

Ejector Retaining Pin

• Precision cut to length
• Hard Chrome Plated

Limited Lifetime Warranty
We are so confident in our Rainier Arms BCG we offer them with a limited lifetime warranty. So if at anytime your Rainier Arms BCG breaks on your during normal use(Intentional abuse & Gas Key wear not included) we will replace it.