Since 2013, Burgu has sold over one million bolt carrier groups under Turkish government contract for MPT55, MPT76, MP5, HK33, G3, and MG3.

Magnetic particle inspected (MPI) to ASTM E1444 aircraft quality inspection standards for molecular soundness and longer life of all the below-mentioned metal parts.

• Carrier: 8620 (20NiCrMo2-2), heat treated (case hardened to SAE-AMS-6875) - QPQ nitride finish.
• Bolt: 14NiCr14, heat treated (case hardened to SAE-AMS-6875) - QPQ nitride finish.
• Extractors: Aircraft quality alloy steel shot peened. Heat treated to military drawing specification SAE-AMS-6875. Phosphated to 5.3.1.3 of MIL-STD-171.
• Gas Key: 4130, aircraft quality steel, heat treated to SAE-AMS-6875 QPQ HT PROCESS
• Cam Pins: Precision machined. Heat treated to SAE-AMS-6875. Phosphated to 5.3.1.3 of MIL-STD-171.
• Firing Pin: Machined and precision ground for accuracy. Heat treated to military drawing specification per SAE-AMS-6875. Chrome lined per 1.2.2 of MIL-STD-171.
• Firing Pin Retaining Pin: Heat treated stainless steel pin contouring the carrier body.
• Ejector: Precision machined. Heat treated to SAE-AMS-6875. Phosphated to 5.3.1.3 of MIL-STD-171.
• Gas Rings: 3 pc. stainless steel per Mil-Spec.