Stern Defense 45 ACP Magazine Block Adapter - Phosphate 8620 Steel AR15

The Stern Defense 004SDBU45D1M transforms standard AR-15 lower receivers to accept .45 ACP magazines, expanding caliber options without requiring a dedicated platform. This magazine block adapter enables shooters to run .45 ACP ammunition through their existing AR-15 setup with reliable feeding and extraction.

What Makes This Different

Unlike universal magazine adapters that require modification or compromise reliability, this Stern Defense block maintains the AR-15's direct impingement system while ensuring proper magazine alignment and cartridge presentation. The phosphate-coated 8620 steel construction provides corrosion resistance and dimensional stability under repeated cycling. This adapter eliminates the need for separate .45 ACP carbine platforms while maintaining the familiar AR-15 manual of arms.

Key Features

• Phosphate-finished 8620 steel construction for corrosion resistance and durability
• Direct drop-in installation in standard AR-15/M16 lower receivers
• Compatible with standard .45 ACP magazines including Glock and 1911 patterns
• Maintains original trigger group and safety selector operation
• Precision-machined magazine well dimensions for secure magazine seating
• No permanent modifications required to host firearm
• Retains last-round bolt hold-open functionality

This adapter performs reliably in both semi-automatic sporting applications and tactical training scenarios. The .45 ACP cartridge provides substantial stopping power with reduced over-penetration compared to rifle cartridges, making it suitable for close-quarters applications. The phosphate coating resists wear from repeated magazine changes and environmental exposure during extended shooting sessions.

Technical Specs

• Material: 8620 steel with phosphate finish
• Caliber: .45 ACP
• Compatibility: AR-15/M16 lower receivers
• Magazine compatibility: Standard .45 ACP magazines
• Installation: Drop-in, no gunsmithing required
• Finish: Black phosphate coating
• Model: 004SDBU45D1M
• UPC: 850001176057

This magazine block adapter represents a cost-effective solution for shooters seeking .45 ACP capability in their AR platform. The proven 8620 steel construction and phosphate finish ensure long-term reliability across thousands of rounds.