The MP38 / MP40 Split Collar Nut Ring is a spring retaining ring used within the front barrel assembly of the MP38 and MP40. Its purpose is to secure the collar nut assembly by applying constant spring tension, ensuring the surrounding components remain correctly positioned during assembly and operation.

Unlike larger external parts, the split collar nut ring is often overlooked during restoration projects. However, without a correctly fitting retaining ring, the barrel collar assembly can develop unwanted movement, making disassembly easier than intended and affecting the stability of the front-end components.

Because this ring relies on its spring tension rather than its size for proper function, accurate dimensions and material properties are essential. A ring that has lost its elasticity or has been distorted during previous disassembly may no longer provide sufficient retaining force.

Manufactured from hardened spring steel, this MP38 / MP40 Split Collar Nut Ring combines strength with the flexibility required for repeated installation and removal. Produced to original specifications, it offers dependable retention while preserving the correct construction of original MP38 and MP40 barrel assemblies.