MGD PM-9

The MGD PM-9 was a French open bolt submachine gun, designed in the late 1940s or early 1950s by Louis Debuit and manufactured in small numbers by French firm Merlin and Gerin in the 1950s.[1] The PM9 was an unusual design in three different ways: it employed off-axis delayed blowback, it had a clock-style spiral mainspring similar to that of the Lewis gun, rather than the cylindrically-coiled spring used in the vast majority of self-loading firearms and, most unconventionally of all, used a rotating flywheel as a delaying mass in conjunction with the bolt.[2] It was furnished with a folding magazine, and some also had folding buttstocks, and this together with its original operating mechanism results in a highly compact weapon, but there is no known record of it being purchased or deployed by any military or police force.[2]

MGD_PM-9
Type	Submachine gun
Place of origin	France
Service history
In service	never
Production history
Designer	Louis Debuit
Designed	late 1940s – early 1950s
Specifications
Length	659 mm (25.9 in) stock extended 359 mm (14.1 in) stock collapsed
Barrel length	213 mm (8.4 in)
Cartridge	9 mm Parabellum
Barrels	213 millimetres (8.4 in)
Action	Delayed blowback
Rate of fire	750 rpm
Effective firing range	100 metres (110 yd)
Feed system	32-round box magazine (MP-40 compatible)
Sights	Iron sights