Description
The BCM KeyMod 4″ Nylon Picatinny Rail Section is a lightweight accessory-mounting segment from BCM, designed to add a short stretch of Mil-Std 1913 Picatinny rail to any KeyMod-compatible handguard or chassis. The mounting footprint sits flush against KeyMod slots and locks in place with the included hardware, giving you a snag-resistant platform for lights, lasers, vertical grips, bipods, or other accessories without committing to a full-length rail.
The rail body is molded from lightweight impact-resistant polymer (nylon), keeping the section’s contribution to overall rifle weight minimal while still providing a rigid mounting surface. Mounting hardware is made of corrosion-resistant stainless steel, and the self-contained assembly installs with standard KeyMod tools. The 4″ length spans seven Picatinny slots, giving shooters a compact, purpose-built mounting area rather than a full-length rail.
Finished in Black and built to Mil-Std 1913 Picatinny arsenal specifications, this BCM-KMR-1913-N4 section is a simple, no-nonsense way to add accessory real estate to a KeyMod handguard or to replace a damaged rail segment.









