Stern Defense MAG-AD9 Glock Magazine Adapter

Drop-in adapter that converts a mil-spec AR-15 lower to post-2004 Glock-pattern 9mm magazines for simple-blowback AR-9 builds.

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Quick Specs

Price: $180
Weight: N/A
Brand: Stern Defense
Category: lower-part

Features

•Mil-spec AR-15/M4/M16 lower conversion
•Post-2004 Glock-pattern 9mm magazines
•6061-T6 aluminum body
•Steel nickel-boron feed ramp
•Last-round bolt hold-open

Capability Boosts

Modularity+2

Recommended For

Duty/Patrol+2

duty+2

Competition+2

customization+2

Compatibility Tags

family: pccfamily: ar-patternplatform: custom-ar-9caliber: 9mmmag-type: glockar9-system: simple-blowback

Overview

The Stern Defense MAG-AD9 locks into a mil-spec AR-15, M4, or M16 magazine well and converts it to use post-2004 Glock OEM magazines with square magazine-catch notches. Its 6061-T6 aluminum body contains a steel feed ramp with a nickel-boron finish and a last-round bolt hold-open system.

This is a simple-blowback conversion, not a universal AR-9 adapter. A 9mm build needs the correct barrel, a Glock-cut bolt, a carbine spring, and a buffer weighing at least 5.4 ounces. Glock G26 and G27 magazines are too short, and Stern lists the adapter as incompatible with CMMG Radial Delayed Blowback and Olympic Arms systems.

Key Features

Installs in a mil-spec AR-15, M4, or M16 magazine well
Uses post-2004 Glock OEM magazines with square magazine-catch notches
6061-T6 aluminum adapter body
Steel feed ramp with nickel-boron finish
Built-in last-round bolt hold-open
Requires a Glock-cut 9mm bolt, correct-caliber barrel, carbine spring, and 5.4-ounce or heavier buffer
Not compatible with CMMG Radial Delayed Blowback or Olympic Arms systems

Pros

+Converts an existing mil-spec AR-15 lower without a dedicated PCC lower
+Adds a last-round bolt hold-open to the conversion
+Uses common post-2004 Glock-pattern 9mm magazines

Cons

−Requires a Glock-cut bolt and a simple-blowback operating system
−Glock G26 and G27 magazines are too short
−Does not work with CMMG Radial Delayed Blowback or Olympic Arms systems

Detailed Specifications

Manufacturer SKU: 001-SD MAG-AD9-GLOCK-9AND40-M
lowerCompatibility: Mil-spec AR-15, M4, and M16 lower receiver contours
magazineCompatibility: Post-2004 Glock OEM 9mm magazines with square magazine-catch notches; G26 and G27 magazines are too short
Material: 6061-T6 aluminum
feedRamp: Steel with nickel-boron finish
boltRequirement: 9mm bolt with Glock magazine cut
bufferRequirement: 5.4 oz or heavier buffer with carbine spring for 9mm
operatingSystem: Simple blowback; not compatible with CMMG Radial Delayed Blowback