The MGD PM-9 is a prototype French submachine gun.
The PM-9 was developed in the late 1940s and early 1950s by Louis Debuit. While prototypes still exist, the weapon never entered service.
The PM-9 was an unusual firearm that used a rotating flywheel as a delaying mass for its bolt. It fires from an open bolt, and uses 32-round MP 40-compatible stick magazines.