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Over the past few years, you’ve probably seen a massive resurgence of the pistol caliber carbine, most notably the 9mm carbine. Stability is the most significant advantage of the pistol caliber carbine over any sidearm. 

You’ve probably also seen some crack shots at the local shooting range who can shoot the wings off a fly at 25 yards with their sidearm. However, for the majority of shooters, handgun accuracy tends to begin dropping off around 15 yards, especially in kinetic situations where the adrenaline is surging and stress levels are through the roof.

The pistol caliber carbine gives you added stability to hit your mid-range targets more accurately and consistently. Maxim Defense recognized this demand in the industry and answered with the MD9 9mm pistol caliber carbine. The Maxim Defense MD9 offers a PDX-like platform chambered in 9mm.

person holding a md9

The Maxim Defense MD9

Maxim Defense MD9 Pistol Caliber Carbine

When you’re looking for Maxim Defense ingenuity in a new standard AR-9, the MD-9 is your answer. The MD-9 was engineered to fit the growing demand for cutting-edge AR9-style rifles for today’s Military and commercial market.

Every MD9 features Maxim’s free-floating barrel and custom handguard for increased comfort and versatility. These handguards provide a monolithic-like upper receiver platform and M-Slot compatibility.


  • Modified Maxim Defense HATEBRAKE
  • M-Rax and M-Slot compatible handguard
  • Military-grade materials
  • 5.8″ barrel
  • ALG Combat Trigger
  • Radian charging handle and selector
  • Maxim CQB stock
  • Ambidextrous magazine release
  • Fully floated barrel
  • The last round holds open
  • Compatible with Glock 9mm magazines (Glock 19 and larger)

man holding an md9


  • Caliber: 9x19mm Parabellum
  • Barrel Thread Pitch: ½-28
  • Material Composition: 7075 Aluminum & tool steel
  • Finish: Nitride / Type III Anodizing
  • Barrel Length: 5.8″ [147.32mm]
  • Overall Length: 20″ [508mm] (collapsed stock)
  • Weight: 6lb 1oz [2.75kg]
  • Barrel Material: 4150 CrMoV
  • Muzzle Velocity: 1,150 FPS (Federal FMJ 124gr)
maxim defense md9

Maxim Defense MD9 featured with its clip



md9 posed against a wall

$1,995.00 at Maxim Defense

What Sets the Maxim Defense MD9 Apart?

The package weighs in at just over six pounds unloaded, and 20 inches collapsed, adding to the small footprint. The MD9 also boasts an ambidextrous magazine release, Radian charging handle, and selector. It accepts all Glock 9mm pattern magazines, G19 or longer. Rounding out the set-up is a modified Maxim Defense HATEBRAKE muzzle booster and ALG Combat trigger.

An issue seen in previous pistol caliber carbine designs is that the shooter would use the magwell for their support grip, which would cause the magazine to move just enough to cause failure to feed malfunctions. Maxim Defense recognized this issue and mitigated it by extending the length of the magwell, giving the shooter a full support hand grip without interfering with the function of the magazine.

The Modified HATEBRAKE emulates the back pressure of a suppressor. So not only is it directing the blast forward and away from the shooter and those around the shooter, but it regulates the cyclic rate. The advantage of this is whether you’re running the included HATEBRAKE or a 9mm suppressor, the cyclic rate will be consistent and not over-gassed.

Maxim Defense went with a barrel length of 5.8″ to maximize the velocity and hence accuracy of this PCC. The optimal barrel length for the 9mm cartridge is roughly 6″, so with the MD9, you’re getting optimal performance out of the 5.8″ barrel. In addition, the MD9 was tested with 124gr FMJ, which resulted in a muzzle velocity of 1,150 feet per second.

When it comes down to defending your home and keeping your family safe, stack the odds in your favor with the Maxim Defense MD9 pistol caliber carbine.

Bud Boomer

Bud Boomer is a former American Sheriff from Niagara County who doesn't like Canadian beer but does enjoy wearing flannel. After many years in law enforcement, followed by a few rotations overseas as a contractor with Hacker Dynamics (on the same PSD team, he's proud to say, as Bert Gummer, Tom Evans, and Walter Langkowski). He was an avid outdoorsman at one time, and will still sleep on the ground if he has to, but nowadays would prefer to stick to day hikes and climbs and sleeping indoors where it's comfy and warm. He has been hopelessly lost in the Canaan Bog at least half a dozen times, but still enjoys practicing land nav there. Bud believes anyone who eats poutine râpée is either a commie or stupid.