Heckler

From Rap Dictionary

noun

Heckler

Short for Heckler & Koch, a German firearm manufacturer responsible for the MP5 submachine gun and your USP handgun, among other types of guns, eg. assault rifles used in several armed forces and law enforcement communities.

"Keep the Heckler close, you know them smokers'll test ya." -- Jay-Z (Dirt Off Shoulder [2003])