Apex 5.00” Slide for FN 509 – RMR Slide Cut

Description

This Apex 5.00” slide is built for the FN 509 platform, designed for California gun owners who want a reliable, competition-ready upgrade without the hassle of non-compliant parts. It arrives stripped, meaning you supply your own internal components from your factory FN 509 slide (full list below) and a 5-inch barrel. All cavities accept genuine FN parts, and Apex components for the 509 drop in for optimized function.

Key Features & Real Benefits

• Front and rear cocking serrations give you a positive grip from either end, making press checks and slide manipulation quick and secure—especially useful under stress or with gloved hands.
• Two serration patterns available: Classic or Lightning Bolt. Both offer tactile texture for a firm purchase, letting you pick the look that fits your style.
• Suppressor-height black-on-black sights are pre-installed by Apex, providing a clear sight picture that co-witnesses with most red dots. No extra trips to the gunsmith—just mount your optic and go.
• Black PVD finish resists wear, corrosion, and holster drag. It holds up to regular range use and stays looking clean without adding bulk.
• Ported slide design works with the Apex ported barrel (sold separately) to vent gases upward, reducing muzzle climb for faster follow-up shots. Note: the ports only function correctly with the Apex ported barrel.

Fitment & Specs

• Requires all internals from your current FN 509 slide (see below for component list) and a 5-inch barrel.
• Compatible with factory FN 5” barrels and Apex drop-in barrels (5.00” standard, 5.00” threaded, and 5.00” ported—ported barrel coming soon).
• Optic cut: RMR footprint. Directly mounts RMR, RMR-HD, SRO, Holosun 508, and similar optics. Torque screws to 20 in-lb maximum unless your optic manufacturer specifies otherwise.

How to Get It Running

• Use your factory parts from your existing FN 509 slide. Simple transfer.
• Order a Slide Completion Kit from Apex (purchased with this slide only; Apex installs it before shipping). Contact their customer service to arrange assembly.
• Buy new FN factory components from Midwestgunworks.com or