SKU: S01508
UPC: 860141001508
MPN: 001-SD MAG-AD9-GLOCK-9AND40-M
The Stern Defense AD9 is a magazine adapter that lets a standard mil-spec AR-15, M4, or M16 lower receiver run Glock 9mm and .40 S&W magazines. It's built for shooters putting together a pistol-caliber carbine without committing to a dedicated 9mm lower. Drop it into an existing lower and you've got a PCC that feeds from the same Glock mags you already carry for your sidearm. The adapter weighs 5.5 ounces and installs in seconds, making it one of the simpler paths to a 9mm AR. You'll find it alongside our other firearm conversion kits.
Stern Defense machines the AD9 from 6061-T6 aircraft-grade aluminum and pairs it with a 4140 steel feed ramp finished in nickel boron coating for slick feeding and corrosion resistance. The body wears a Type 3 hard-coat anodized finish. What separates this adapter from a basic conversion block is the rolling actuator bolt-stop lifter, which gives you proper last-round bolt hold-open when the magazine runs dry — a feature most drop-in blocks skip. An ergonomic magazine release and built-in catch are part of the unit, so you're not robbing parts from your existing lower. It accepts all generations of Glock 9mm and .40 S&W magazines, from compact to full-size and extended sticks.
This adapter makes sense for anyone building a budget-friendly range carbine, a home-defense PCC, or a suppressed 9mm setup that shares magazines with a Glock pistol. Because it works with standard Glock mags, ammo and feeding logistics stay simple across your kit. Pair it with the Stern Defense rapid-attach buttstock adapter if your lower needs a stock solution, or look at the same maker's M&P and SIG P320 adapter if you run a different pistol pattern. Browse the full lineup of conversion options to match your build.
This specific adapter is built for Glock 9mm and .40 S&W magazines, and it works with all generations of Glock mags from compact to extended. If you run M&P or SIG P320 magazines, Stern Defense makes a separate variant for those patterns.
Yes. The AD9 uses a rolling actuator bolt-stop lifter that engages the bolt catch when the magazine runs empty, so the bolt locks back on the last round. Many drop-in conversion blocks in this class do not offer that feature.
It's designed for standard mil-spec AR-15, M4, and M16 lower receivers. The adapter drops into the magazine well and installs in seconds, with its own magazine catch and release built in.
The body is machined from 6061-T6 aircraft-grade aluminum with a Type 3 hard-coat anodized finish. The feed ramp is 4140 steel with a nickel boron coating for smooth feeding and corrosion resistance. It's made in the United States.
The AD9 weighs 5.5 ounces per manufacturer specifications, so it adds minimal weight to a finished pistol-caliber carbine build.
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