The MDR (an acronym for micro dynamic rifle) is a family of autoloading bullpup rifles designed by Desert Tech (formerly Desert Tactical Arms) in 2014. A second generation version of the rifle is marketed as the MDRX (an acronym for micro dynamic rifle eXtreme). In 2018 a military version of the MDR, the NGSAR, was submitted, but was not one of the finalists in the United States Army Next Generation Squad Weapon Program trials to replace standard issue US army Infantry Weapons.
The MDR's first public debut was in 2014 at Shot Show.
Design
The Desert Tech MDR is a gas operated, conventional rotary bolt bullpup rifle. The gas system features a gas piston located above the barrel and a 6 position manual gas regulator.
The MDR rifle is designed to be ambidextrous. The MDR contains an ambidextrous forward and side eject port and viewing window that allows for tool free forward ejector side change. A non reciprocating ambidextrous charging handle is installed on both sides of the gun, and two or three-position safety / selector levers and magazine release are provided on both sides of the pistol grip. The rifle is compatible with Desert Tech caliber conversion kits that allow the rifle to change caliber. This provides a unique feature in which the rifle chassis can accept both intermediate cartridges and full-powered rifle cartridges on the same serial number platform (such as 5.56×45mm NATO and 7.62×51mm NATO magazines).
The outer shell of the gun is made from impact-resistant polymer with an aluminium receiver.
Many of the MDR rifle components are produced using modern Metal injection molding (MIM) metalworking processes that are becoming more common in the firearm industry. MDR MIM parts including the Barrel Block (Trunnion), Gas Block, Bolt Catch, 7.62 mag conversion bar, ejector retainer, and extractor link, are produced by Indo-MIM Pvt. Ltd., India. Indo-MIM Pvt, Ltd received the 2017 distinction in hand/tools award by PIM international for their innovation in MIM development and part cost reduction.
The .308/7.62 MDR was 10,000 round endurance tested with .308 win 150 grain FMJ American Eagle, 7.62x51 149 grain American Eagle, 7.62 m80 ball US Surplus and averaged 1 failure in 2000 rounds.
NGSAR Prototype, Modified MDR for NGSW
In 2018 a modified MDR family rifle, the NGSAR, chambered in a proprietary 6.8mm polymer-cased ammunition cartridge made by PCP was selected as one of the United States Army's Next Generation Squad Weapon Program (NGSW) weapons trial finalists to replace the United States Army's 5.56×45mm NATO caliber weapon systems. Desert Tech partnered with PCP tactical who provided a custom ammunition solution. The NGSAR was trialed in a carbine and automatic rifle configuration and were ultimately rejected.
The NGSAR rifle included improvements in the design such as a T-Worx battery powered integrated data rail, onboard round counter, longer receiver, bolt carrier, barrel extension, charging handle, forward eject system, barrel mounting system, proprietary 6.8mm PCP magazines, custom flow reflex suppressor, CNOD day/night optic.
MDR .308/7.62 upgrade program
The 2017 MDR in .308/7.62 win received public feedback that resulted in an upgrade program by Desert Tech on the gas and extractor system in 2019 to improve the rifle's ammunition tolerance without having to adjust the gas setting as frequently. This update is considered the Generation 2 MDR Gas System.
Desert Tech publicly addressed the MDR criticism on January 10, 2019. Desert Tech directly attributed the most vocal criticism of the platform to the InRangeTV company in collaboration with the Forgotten Weapons Company that demonstrated numerous failures in the system that were identified to be from varying ammunition loads used in the gas system on December 13, 2018. In addition to addressing the criticism, Desert Tech provided a technical root cause analysis presentation on the platform failures and resulting improvements with the generation 2 gas system. As a supplemental incentive, Desert Tech announced their MDR generation 2 gas system upgrade was to be covered under their warranty program for all owners.
MDRX redesign
The Micro Dynamic Rifle eXtreme, MDRX, variant was produced and marketed as a separate firearm in 2020. Improvements to the firearm include the following: Improved impact-resistant polymer, improved trigger, improved gas block, and a new "Ratchet" compensator.