The Maxim Defense MDX is a compact AR-pattern firearm series engineered as a step up in size from the ultra-short PDX, offering improved ballistic performance while maintaining a highly compact footprint. Built around Maxim’s proprietary receiver set, it is available in multiple configurations including pistols, SBRs and rifles with barrel lengths typically ranging from 8.5" to 16". The platform incorporates a free-floating barrel, M-Slot compatible handguard, and Maxim’s signature SCW or CQB stock/brace systems that significantly reduce overall length. Designed for close-quarters engagements & tactical applications, the MDX series is chambered in 5.56 NATO, .300 AAC Blackout & 7.62x39, offering versatility across defensive, duty and compact rifle roles. In terms of reliability & performance, the MDX is engineered as a fully integrated system using high-grade materials such as titanium, stainless steel and aircraft-grade aluminum to ensure durability under demanding conditions. The platform commonly features Maxim’s HATEBRAKE muzzle device, which helps reduce recoil, redirect blast forward & improve cycling efficiency in shorter barrel configurations. Combined with optimized gas systems and proprietary components, the MDX delivers consistent operation, strong recoil control, and improved reliability compared to standard compact AR builds. Maxim Defense has established a reputation for innovation in PDW-style firearms & the MDX reflects that focus with high-end construction, dependable performance and adaptability across multiple configurations.