Maxim Defense, best known for the company's ultra-compact CQB Stocks for AR-15 and SIG MCX rifles, jumped into the complete-rifle game with themost interesting ultra-compact AR rifle I’ve seen at SHOT Show 2019: the18.75-inch-long Maxim PDX. It is currently available chambered in 5.56 NATOand 7.62x39, with 300 Blackout expected to drop in the second quarterof 2019, and ships in both pistol-brace and SBR configurations.
I’m deeply skeptical of most ultra-compact, rifle-caliber guns,especially because they tend to be portable flashbang generators withpoor blast/flash management. The PDX was clearly designed to addressthis problem head-on, as it integrates Maxim’s HateBrake, which combinesa linear compensator with a substantial blast-director device.
Despite having an ultra short 5.5-inch barrel behind the HateBrake, theultra-slow-motion videos of a PDX in 5.56 NATO being fired in full darknessshowed virtually no muzzle flash. The same gun fired without theHateBrake generated a massive fireball and visible concussion wave. Short of attaching a suppressor and making the gun substantially longer,the HateBrake is one of the few effective solutions we’ve seen fortaming the blast from a tiny AR. Naturally, Maxim Defense has mounted the company's rugged yet compact CQBcollapsible stock on the PDX, which only extends 4 inches from the rearof the receiver when collapsed. The CQB stock does not interfere withany aspect of the gun’s controls when collapsed or deployed, and the PDXcan be fired without extending the stock if desired. When it’s time torock and roll, the CQB stock can be pulled briskly to full extensionwithout fumbling for a latch or lever.
The PDX will be shipping in February 2019 with an MSRP of $2,299, withthe 5.56 and 7.62x39 versions available immediately, and the .300Blackout PDX that I’m excited to try is scheduled to ship in Q2 2019. The HateBrake is available separately for $200 to $240 MSRP, depending on caliber and muzzle-thread configuration.