The Stern Defense 004SDBU45D1M 45 ACP Mag Phosphate 8620 Steel AR15/M16 bolt assembly is purpose-built for shooters who want reliable 45 ACP performance in their AR platform. Machined from durable 8620 AISI steel and finished in a mag phosphate coating, this bolt is designed to drop into Mil-Spec and Glock-pattern upper receivers while working seamlessly with Colt SMG and Glock magazines.

This complete bolt assembly arrives ready to run, with the firing pin, spring, retaining pin, extractor, extractor spring, and proprietary center and roll pins already installed. The updated 45 ACP bolt design is tailored to work smoothly with single-stage triggers that feature short resets, making it a solid choice for range use, training, and general shooting setups built on the AR15/M16 platform. Stern Defense’s attention to detail and engineering focus are evident in the way this bolt balances durability, compatibility, and clean function.

Key Features:

• Manufacturer: Stern Defense
• Model: 004SDBU45D1M
• Caliber: 45 ACP
• Material: 8620 AISI Steel
• Finish: Mag Phosphate
• Compatibility: AR15/M16, Mil-Spec and Glock-Pattern Upper Receivers
• Included Components: Complete Bolt Assembly With Firing Pin, Spring, Retaining Pin, Extractor, Extractor Spring, Center And Roll Pins
• Trigger Compatibility: New Bolt Design Supports Single-Stage Triggers With Short Resets