.45 ACP. 3.5" barrel length. SN: 065. Matte blued overall with polished blued small parts, and mounting checkered black synthetic grips. Manually operated DAO pistol fed by a detachable single stack magazine and mounting fixed rear notch and matted front ramp sights on a matted rib. Standard markings include SEMMERLING CORP./BOSTON, MASS. behind cocking serrations on left slide and MOD. LM-4/PATENTS PENDING forward. Right slide struck STD. MIL. SPEC. CTG. ONLY forward of cocking serrations and CAL. 45 ACP behind them.

Designed by Philip R. Lichtmann and patented in 1977, the Semmerling LM-4 pistol was offered for sale beginning in 1979 as a large caliber backup gun for the discerning buyer. Despite its outward appearance, the handgun is manually cycled either by grasping the slide with the supporting hand or by flicking the weapon aggressively in the event the user must rely on only one hand. Though unorthodox, this method of operation permitted the handgun to be produced in an extraordinarily compact size for its caliber. From the top of the rear sight to the base of the magazine floorplate, the pistol measures 3.75 inches. At approximately 5.25" in length, the handgun offered a .45 ACP weapon in a package small enough for ankle carry.

Despite these advantages, the pistol's method of operation remained slower than a contemporary double-action revolver. Paired with its exceptional cost of $645 (Approximately $2,470 as of 2025), this unorthodox pistol failed to achieve great market success. Approximately 600 examples were produced in total, rendering it a rare and fascinating development in subcompact carry technology. {MODERN}