UMP

UMP is a three letter acronym that could mean:

"Ump" is also a US slang term for "umpire";

Heckler & Koch UMP

The UMP (Universale Maschinenpistole, German for "Universal Machine Pistol") is a submachine gun developed and manufactured by Heckler & Koch. The UMP has been adopted by various agencies such as the U.S. Customs and Border Protection. Heckler & Koch developed the UMP as a lighter and cheaper successor to the MP5, though both remain in production.

Design details

The UMP is a blowback operated, magazine-fed submachine gun firing from a closed bolt.

As originally designed, the UMP is chambered for larger cartridges (.45 ACP and .40 S&W) than other submachine guns like the MP5, to provide more stopping power against unarmored targets (with slightly lower effectiveness at longer range) than the MP5 (largely offered in 9×19mm, albeit with short-lived production of 10mm Auto and .40 S&W variants). A larger cartridge produces more recoil, and makes control more difficult in fully automatic firing. To mitigate this, the cyclic rate of fire was reduced to 650 rounds/min (600 rounds/min for the UMP45), which makes it one of the slower firing submachine guns on the market.