The Maxim Defense PDX is chambered in 7.62x39mm with a 5.5-inch barrel, a short-barreled configuration; transfer requires additional federal paperwork. It has a 20+1 round capacity and ships in black. The platform is built on the AR pattern. 
 

Key Specifications 

• Brand: Maxim Defense 
• Model: PDX 
• Caliber: 7.62x39mm 
• Action: Semi Auto 
• Capacity: 20+1 
• Barrel Length: 5.5 in 
• Color/Finish: Black 
   

Detailed Features 

• 5.5-inch barrel; short-barreled configuration requiring additional federal paperwork 
• 7.62x39mm chambering in an AR-pattern platform 
• 20+1 round capacity 
• Blue/black finish 
• Compact PDX form factor from Maxim Defense Industries

Owners of the Maxim Defense PDX acknowledge it occupies a very specific niche: maximum compactness in an AR-pattern package chambered in 7.62x39mm. Those who buy it know what they are getting and the reviews tend to reflect satisfaction with the concept, even when the execution draws complaints about price.

The 5.5-inch barrel generates significant muzzle blast, which is the most consistent complaint in user accounts. Running the PDX suppressed is the common recommendation from repeat owners. Reliability with the 7.62x39 cartridge and AR-pattern magazines gets mixed reports depending on which magazines are used.

The build quality of the PDX is generally regarded as high-end for the short-barreled AR segment. The cost is a barrier for most buyers, and owners who step up from budget alternatives often note a tangible difference in fit and finish. The PDX splits opinion on whether the price premium is justified for practical use versus the appeal of the platform itself.