Original Item: Only One Available. This is an original German WWII MP40 lower frame assembly manufactured by ERMA in 1941. It includes the rear receiver cup and frame, trigger group, folding shoulder stock, and most of the original dark brown Bakelite components. The receiver tube is not included.

This item is sold as a historical firearm parts assembly only. It does not include the receiver tube, barrel, bolt, or other components required to assemble a complete MP40. Federal, state, and local laws governing firearm components and machine gun parts vary, and the purchaser is responsible for confirming that possession, purchase, and transfer are lawful in their jurisdiction.

The rear receiver cup is marked:

MP40
ayf
41

The manufacturer code ayf identifies ERMA, or Erfurter Maschinenfabrik B. Geipel GmbH of Erfurt, while the number 41 indicates 1941 production. ERMA developed the MP38 and MP40 series and was one of the principal manufacturers of the MP40 during WWII.

The receiver cup is serial numbered:

8150 b

The same complete serial number is stamped on the front of the trigger housing. The shortened serial number:

150

is stamped on both sides of the folding stock near its forward attachment, indicating that the principal serial numbered metal components are matching.

A Waffenamt inspection marking:

WaA165

appears beside the serial number on the receiver cup, with the same inspection marking also present near the rear sling slot.

The rear Bakelite component is separately marked:

715
Eagle / 288

This number does not correspond with the shortened serial number 150 found on the folding stock. The Bakelite component should therefore be regarded as a period replacement or mismatched part rather than part of a completely matching assembly.

The trigger remains movable, and the sear can be seen operating inside the lower frame beneath the area where the receiver tube would normally be installed. This observation describes the present mechanical movement of the parts only and is not a guarantee of function if incorporated into another assembly.

The folding shoulder stock remains operational. It extends and locks into position as intended.

The exterior metal surfaces display a predominantly oxidized patina, with scattered peppering and areas of light pitting. Most of the original blued finish has worn away, though protected bluing remains visible along the upper surfaces that were originally covered by the receiver tube.

The dark brown Bakelite components show extensive service wear and age related damage. The receiver shroud is cracked completely through immediately forward of the trigger assembly. Additional material is missing from the front around the frame latch.

Both Bakelite grip panels show wear. The left grip panel has a crack extending through the material approximately one inch below its upper edge. These damaged areas should be handled carefully to prevent additional loss.

With its matching receiver cup, trigger housing, and folding stock numbers, clearly marked 1941 ERMA production code, retained Waffenamt inspections, functioning stock mechanism, and substantial original Bakelite, this is a highly displayable MP40 parts assembly. The mismatched rear Bakelite component, oxidized metalwork, pitting, cracked shroud, missing material, and damaged grip panel are fully disclosed. It would make a noteworthy addition to an MP40, ERMA production, German WWII small arms, or military firearm component collection.

History of the MP40

The Maschinenpistole 40 ("Machine pistol 40") descended from its predecessor the MP 38, which was in turn based on the MP 36, a prototype made of machined steel. The MP 36 was developed independently by Erma Werke's Berthold Geipel with funding from the German Army. It took design elements from Heinrich Vollmer's VPM 1930 and EMP. Vollmer then worked on Berthold Geipel's MP 36 and in 1938 submitted a prototype to answer a request from the Heereswaffenamt (Army Weapons Office) for a new submachine gun, which was adopted as MP 38. The MP 38 was a simplification of the MP 36, and the MP 40 was a further simplification of the MP 38, with certain cost-saving alterations, most notably in the more extensive use of stamped steel rather than machined parts.

It was heavily used by infantrymen (particularly platoon and squad leaders), and by paratroopers, on the Eastern and Western Fronts. Its advanced and modern features made it a favorite among soldiers and popular in countries from various parts of the world after the war. It was often erroneously called "Schmeisser" by the Allies, despite Hugo Schmeisser's non-involvement in the weapon's design and production. From 1940 to 1945, an estimated 1.1 million were produced by Erma Werke.