The Desert Tech Micro Dynamic Rifle, more commonly known as the MDR, is an American bullpup modular assault rifle.
The MDR was first shown off by Desert Tech in 2014 at the 2014 SHOT Show. Originally slated to enter production in 2015, it was not actually produced until 2017 when people began to start regarding the MDR as vaporware. The MDR was designed to be of a modular design that allows for mission-specific adaptability, simply by changing parts such as the barrel and magazine.
The MDR is of a bullpup design and is completely ambidextrous, which helps with shoulder transitions. The MDR was also designed to be as compact as possible, which allows it to maintain as much accuracy, power or speed while retaining a short overall length. The MDR can switch between multiple calibers, including one with .223 Wylde chamberings, which allows it to fire both 5.56mm NATO and .223 Remington. To help with accuracy, the MDR's barrel is free-floating, and its gas block is incorporated into the integrated Picatinny rail.
The MDR, with the change of a few parts such as the magazine, magazine well adapter, barrel assembly and bolt head, can be chambered for 4 different calibers; .223 Remington, 5.56mm NATO, 7.62mm NATO and the sub-sonic .300 Blackout.