Stern Defense MAG-AD9 AR-15 Magazine Adapter – 9mm / .40 S&W, Glock Mag Compatible

The MAG-AD9 (Mfr # 001SDMAGAD9GLOCK9AND40) slides into a standard AR-15 magazine well and locks via the rifle’s existing mag-catch; installation takes seconds and requires no tools. Its hard-coat Type III anodized finish resists wear, while a 4140 NiB-coated feed ramp ensures reliable feeding. Compatible with all generations of Glock 17/19/22/23/34/35 magazines and most pistol-caliber bolts, the adapter preserves your original fire-control group, buffer, and stock.

Why It Stands Out

• LRBHO mechanism gives true last-shot lock-back—rare on PPE-style magwell adapters.

• Aircraft-grade 6061-T6 aluminum body & 4140 steel internals keep weight to ~5.5 oz while maintaining strength.

• Ergonomic ambi mag-release mirrors the feel of a Glock pistol for intuitive reloads.