[3] The goal of the LM4 was to achieve a combination of the highest practical firepower in as small and light a gun as possible, so as to be easily concealable.

This was approached by selecting the service caliber of .45 ACP for its proven stopping power and opting for a manual repeating mechanism to minimize bulk and weight and ensure flawless operation in the most difficult situations.

Every pistol was Magnafluxed (a method of testing ferrous metals for surface and subsurface flaws) twice in their assembly.

During 2005, the largest collections of Semmerlings comprising examples of the LM1, LM2, LM3, LM4 and the XLM along with all prototypes, tooling, drawings, production and testing equipment, advertising materials and leather accessories were provided to the National Firearms Museum, the Cody Firearms Museum and the Smithsonian.

The XLM also had a threaded barrel with a slide lock allowing for suppressed operation both in semi and quieter non-actuating mode.

For carry, the slide is locked in the closed position by means of a tiny lever located in the middle of the weapon.

A semi-automatic variant known as the Lichtman Model Semmerling 3 was developed as a back up pistol intended for the US Armed forces.