The 5.45x18 MPTs (Malokalibernyj Pistolentyj Tsentralnogo boya – small-bore pistol centerfire) cartridge was developed in 1971-72 in the State Technical Institute of Precision Machine Building (TSNII TochMash), for use in easily concealable pistols then in development at the request of the KGB. The case is rimless and bottlenecked (i.e. the diameter of the body of the case is greater than the caliber), and unlike most other Soviet military cartridges, is made of brass rather than steel. Bullets are pointed and jacketed. Initially, only one bullet was produced, with a combination mild steel / lead core; during the nineties, when the PSM pistols were exported to Europe for sale in commercial markets, another type of bullet was produced, with a soft lead core. This cartridge is known for serious penetration (considering its tiny size), but the stopping power is marginal to say the least.
