Ruger MP9

The Ruger MP9 is a 9×19mm submachine gun/machine pistol introduced by Sturm, Ruger & Co. in 1995. The MP9 was designed by Uziel Gal, designer of the Uzi.
History and design.
In the late 1980s, Gal, designer of the Uzi, improved his design. During this time, American gun manufacturer Sturm, Ruger & Co., bought the rights to the Uzi. New materials such as Zytel polymer brought the Uzi to modern standards. The MP9 entered Ruger's catalogs in 1995.
However, despite recognition as the "improved Uzi" by its creator, the MP9 never took off, with only a few examples produced. The failure of the MP9 meant Ruger is yet to re-enter the submachine gun market since the MP9 left production in 1996, focusing instead on their renowned line of pistols and revolvers.
The MP9 is intended for American government agents for use of close quarters defense, but was poorly received. Accordingly, the MP9 was a short-lived and rare modern firearm, while the older Uzi lives on under production across the globe.
During the Burundian Civil War, Burundian freedom fighters used Ruger's MP9s.
Operation.
The MP9 was designed by Gal as an attempt to improve upon the Uzi. The MP9 uses a hammer-fired closed-bolt design. Foundational elements, such as the blowback operating action, are similar with minor improvements for efficiency. Similar to the Uzi, the MP9 was designed around simplicity, with these combination of factors leading the MP9 to be named the "improved Uzi".
Other changes Ruger and Gal designed into the design included a change of materials. Development of polymers during the 1980s inspired the designers to adopt those materials: the lower receiver and pistol grip of the MP9 are manufactured from Zytel©, a polymer designed during the 1980s. The polymer butt-stock connects to the frame via a polymer hinge.
The MP9 has a three-position switch co-mingling the 'safety' and 'fire' selector: the upper position of the lever indicates the MP9 is "safe" (aka non-firing), the mid-position causes the MP9 to operate in semi-automatic mode, the bottom position switches the MP9 to automatic mode so the 32-round magazine can be emptied in less than two seconds.
The MP9 has a firing-pin block to prevent the MP9 from an impact-related negligent-discharge if the MP9 is dropped.
The MP9 has a detachable barrel cushioned by a spring while the bolt was closed to reduce the effects of recoil.
The MP9 cocking-handle is on top of the MP9 stainless-steel receiver.