Description
Maxim Defense built its name on ultra-compact PDW-style firearms, and the MD9 904S is that philosophy applied to a 9mm AR platform. This is a factory short-barreled rifle with a 4.5 inch free-floated barrel and Maxim's SCW stock, one of the shortest telescoping stock systems on the market. Collapsed, the whole package tucks away small enough to disappear into a backpack, and it shoulders quickly when you need real stability behind a red dot. The Flat Dark Earth Arid anodized finish gives it a clean, uniform look that stands apart from the usual black rifle crowd.
Why the MD9 904S Runs Glock Mags
Instead of locking you into a proprietary magazine, the MD9 feeds from Glock 9mm pattern magazines, G19 length and longer, and it ships with a 33 round stick. If you already keep a Glock in the safe, your mags pull double duty. The lower features an ambidextrous magazine release, and Maxim paired it with a Radian Talon ambi safety and Radian Raptor charging handle, so lefties get a genuinely usable setup rather than an afterthought.
Parts List That Reads Like a Custom Build
Plenty of factory guns make you budget for upgrades on day one. This one does not. The ALG Defense Combat trigger breaks clean and resets fast, the BCM Gunfighter grip fills the hand well, and the M-LOK compatible handguard mates to the upper for a monolithic-style feel with room for lights and hand stops. Materials and coatings are held to a military-grade standard throughout, which is what you would expect from a company that supplies hardware for professional users.
Where the MD9 904S Earns Its Keep
A 9mm blowback gun this size is a natural for home defense, truck duty, or just an outrageously fun range day. Recoil is soft, ammo is affordable, and the short sight radius pairs perfectly with a compact optic. Add a suppressor down the road and you have one of the quietest, handiest setups you can put together on this platform.
Key Specifications
- Manufacturer: Maxim Defense Industries
- Model: MD9 904S
- Manufacturer Part Number: MXM-49713
- UPC: 680017497132
- Product Type: Short Barrel Rifle (SBR)
- Action: Semi-Auto
- Caliber: 9mm
- Barrel Length: 4.5 in
- Capacity: 33 Rounds
- Magazine Compatibility: Glock 9mm pattern, G19 length and longer
- Finish: Flat Dark Earth (Arid) Anodized
- Stock: Maxim Defense SCW PDW-Style Stock
- Trigger: ALG Defense Combat Trigger
- Charging Handle: Radian Raptor
- Safety: Radian Talon Ambidextrous
- Grip: BCM Gunfighter
What’s Included
- Maxim Defense MD9 904S 9mm SBR
- One 33-round Glock pattern magazine
- Owner's manual
Frequently Asked Questions
What magazines does the Maxim Defense MD9 904S accept?
It runs Glock 9mm pattern magazines, which is a big part of its appeal. Maxim recommends G19 length or longer, so 15-round mags on up through 33-round sticks and even drums all work. The included magazine holds 33 rounds.
Is the MD9 904S good for left-handed use?
Yes, it's one of the better setups out there for southpaws. The Radian Talon safety selector is fully ambidextrous, the magazine release works from both sides, and the Radian Raptor charging handle can be run with either hand. You won't feel like the controls were designed against you.
How does a 4.5 inch barrel handle in 9mm?
Really well, since 9mm was designed for short barrels in the first place. You lose far less velocity than you would cutting down a rifle cartridge, and the blowback action keeps things simple and reliable. The result is a soft-recoiling, quick-pointing gun that thrives inside close quarters distances.
Can I mount accessories on the MD9 904S handguard?
You can. The handguard is M-LOK compatible and mates to the upper receiver for a monolithic-style layout, so lights, hand stops, and other add-ons bolt right up. It's also compatible with Maxim's M-RAX accessory system if you want to stay in their ecosystem.






Reviews
There are no reviews yet.