The Semmerling was a somewhat overrated stainless 45 that was the smallest 45 available . Looked like an auto but had to be racked back for every shot.
The original Semmerling was tool steel...the A.D."Simmerling"was a stainless steel copy,
and not thought of as highly as the original, but still priced exorbitantly. From Wiki:
The Semmerling series of pistols included the LM1, LM2, LM3, LM4 and XLM. The only version available to the public was the LM4 which was first designed and manufactured in the U.S.A. in the early 1980s and marketed at a price of US$750. The "LM" in the model numbers stands for "Lichtman Model", after the inventor of the design, Philip R. Lichtman. Lichtman applied for and received at least four United States Patent's related to the design.
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. Because of this the LM4 was first offered to the U.S. Army and government agencies.
The Semmerling LM4 has 33 parts (including screws), making it one of the simplest guns ever made. In the original design, every part except for the springs was made of high-quality S-7 tool steel. Every pistol was Magnafluxed (a method of testing ferrous metals for surface and subsurface flaws) twice in their assembly, making the LM4 one of the most carefully constructed pistols produced.
Each pistol was essentially handmade to order with production averaging a little over ten pieces a month, while maintaining very strict quality control procedures to ensure a high degree of reliability and functionality. Of the LM4 model,
only about 600 were ever produced.
A stainless steel version, not part of the Semmerling Corporation's efforts, has been available at request from the American Derringer corporation since about 1995.