Apex Offers Upgrades For The FN 509 Midsize MRD
This guide details the installation of the Apex 5-inch Barrel & Slide Assembly for the FN 509 Midsize MRD. The Apex assembly is a drop-on part designed for ease of installation, requiring the transfer of the factory recoil assembly. It features a matched slide mass for reliable cycling, a universal optic mounting system compatible with the FN 509 Tactical mounting standard, and includes an Apex Heavy Duty Striker. The process is presented as a straightforward upgrade for FN 509 owners seeking enhanced performance and modularity.










