Built in the early 1980s and originally offered only to U.S. Army and government agencies, the Semmerling line of manual repeaters included the world's smallest and most powerful multi-shot pistols ever offered. Chambered for the military standard .45acp "ball" cartridge, the 1-inch wide Semmerling lm4 was a design variant boasting only 33 parts that was offered as an amazing combination of practical stopping power, reliability and ease of concealment. Fully loaded with five rounds, the compact Semmerling lm4 pistol weighed less than 20 ounces.
Constructed primarily of S-7 tool steel, the Semmerling line of pistols included the xlm, the only semi-automatic version, made for a military contract. But the standard Semmerling locked-breech handguns provided memorable recoil and required manually cycling the barrel forward to eject the fired case, then backward to feed another cartridge into the chamber. Quality control was high on the assembly line, with each Semmerling pistol being Magnafluxed twice to detect any hidden metallurgical flaws. About 600 Semmerling lm4 pistols were manufactured.
In 2005, an extensive collection of Semmerling handguns was donated to the National Firearms Museum, and today visitors to the galleries can see each of these pieces reflected in an exhibit aptly entitled "Mother of Invention," where the Semmerling shares the spotlight with other innovative designs like the Bren Ten, Dardick, Gyrojet and others.