Midwest Industries 556 Bolt Carrier Group C158 Carpenter Steel Black Nitride Coating MI-BCG-NIT

• Black Nitride finish
• Properly heat treated
• Final grind before plating

· 9310 Steel 5.56/.223 bolt· Shot peened· Black Nitride finish· 4140 Gas Key

• Black Nitride finish
• Properly torqued with Grade 8 fasteners
• Properly staked to ensure reliability

· 4140 Cam Pin

• Heat Treated
• Black Nitride finish

· Machined from solid 4140 bar stock, heat treated and shot peened· Extractor insert included· Firing pin precision machined from 17-4 H-900 Stainless Steel· Midwest Industries Limited Lifetime Warranty