Mean Arms Ar-9 Endomag 9mm 30-Round

The Mean Arms AR-9 Endomag 9mm 30-round magazine conversion system lets you build a 9mm AR without replacing your mag well or wrestling with adapter plates. Instead of forcing a pistol magazine into an AR-15 platform with a bulky insert, Mean Arms flipped the problem: they engineered a retrofit that converts standard Magpul PMag Gen 2 or Gen 3 magazines to reliably feed 9mm ammunition. If you're running a Glock or Colt 9mm bolt-carrier group in your lower, this conversion handles the geometry mismatch and feeds whatever 9mm ammo you have on hand.

The appeal is straightforward. You get a clean, adapter-free setup that plays nicely with the AR ecosystem most shooters already know. No proprietary magwell hardware to source or fiddle with. The conversion comes factory-ready for 30-round capacity, and Mean Arms designed it to be modifiable if you want to swap it to a 10- or 20-round magazine down the road. That flexibility is handy if your local rules or preferences shift.

Whether you're assembling a 9mm AR for plinking, home defense, or just exploring what the platform can do in a softer-shooting caliber, this conversion keeps things simple and reliable. It's the kind of thoughtful solution that makes a 9mm AR actually fun to feed and shoot without compromise.

Key Features

• Converts standard Magpul PMAG Gen 2 or Gen 3 magazines to feed 9mm rounds
• Compatible with Glock and Colt 9mm bolt-carrier groups
• No magwell adapter or insert required
• 30-round capacity (modifiable to 10 or 20 rounds)
• Reliable feeding with all brands of 9mm ammunition

Specifications

Frequently Asked Questions

Will this work with any 9mm AR-15 lower?

The Mean Arms Endomag conversion is designed for use with Glock or Colt 9mm bolt-carrier groups. Compatibility depends on both your BCG type and your magazine well; no adapter is needed with this system, but confirm your BCG type before purchasing.

Can I use a different magazine with this conversion?

The conversion is engineered for standard Magpul PMAG Gen 2 or Gen 3 magazines. Those are the magazines you'll modify with this kit.

Can the 30-round magazine be converted to a different capacity?

Yes. The kit comes factory-ready for 30-round capacity, but it can be modified to fit 10- or 20-round magazines if needed.

What 9mm ammunition will it feed?

Mean Arms rates the conversion for reliable performance with all brands of 9mm ammunition.