The MP-9 came from a design that a Swedish company Interdynamic AB of Stockholm had for a cheap submachine gun for military applications. Interdynamic was unable to drum up any interest among governments, and the subgun never entered production in Sweden. Unwilling to give up on the design, Interdynamic set up a U.S. subsidiary intended principally to market a semiautomatic version, named the KG-9 after the two principal partners Kelgren & Garcia, to civilians. More about Kelgren and Garcia can be found under Intratec TEC-DC9.
Interdynamic U.S.A. was forced by the BATF to redesign the KG-9 due to its ease of being converted to full auto. At the same time as a closed bolt being designed, per the BATF, the lower plastic receiver had to be retooled to place a metal serial number tag in the side as opposed to just stamping the serial number in the plastic magwell. This version was named the KG-99 and it is this gun that was offered in an open bolt submachine gun configuration designated the MP-9. Placed side by side, the KG-99 and MP-9 upper and lower receivers are identical with the exception that the MP-9 has a bolt hold open slot milled in the upper and the tip of the muzzle has a compensation slot cut into it. Interdynamic produced a... Read More