magpul pdr
The PDR (personal defense rifle) is an American-designed compact assault rifle, developed by Magpul Industries in Colorado. It is designed for the same role as the FN P90 and has similar ergonomics, but fires NATO standard 5.56x45mm ammunition and uses the same magazines as the M16 to simplify logistics.
Thus far the PDR has not progressed beyond the prototype stage, and development seems to have been halted.