SMG - 5.56x45mm NATO - Germany - 700 RPM - While not a factory weapon, the HK 53K has been created by custom gunsmiths such as F.J. Vollmer from a combination of MP5K and HK 53 parts.  In other words, it is an MP5K-sized HK 53!  While it maintains the power of the 5.56mm NATO cartridge, the blast and flash signature is at best unpleasant. (c)D.E. Watters
