5.45×18mm MPTs (7N7) is a Russian pistol cartridge. It is chambered in the PSM pistol and OTs-23 Drotik machine pistol. It was designed in the Soviet Union in the early 1970s by Antonina D. Denisova at the Precision Mechanical Engineering Central Research Institute (TsNIITochmash). The development was done in concert with that of the PSM. Though the pistol was originally intended to be a pocket pistol for issue to high-ranking Soviet officers, it has reportedly found popularity amongst police and KGB officers as an easily concealed and suppressed operational pistol.