Apex 5.00” Slide for FN 509 - RMR Slide Cut
Specs at a glance
About this product
This is the Apex 5.00” Slide for FN 509 - RMR Slide Cut, a stripped, black PVD-coated slide built to upgrade your FN 509 with a longer sight radius and direct-mount red dot capability. You supply your factory internals and a barrel; Apex does the rest. Per Apex specs, this slide accepts all factory FN 509 internals and is optimized for Apex’s own ported barrel and trigger components. It comes with suppressor-height black-on-black sights installed, front and rear cocking serrations, and your choice of Classic or Lightning Bolt serration pattern. At $400, it’s a straightforward way to turn a compact 509 into a competition-ready or duty-oriented handgun.
| Manufacturer | Apex Tactical Specialties (per manufacturer specs) |
|---|---|
| Model | 5.00” Slide for FN 509 – RMR Cut |
| Material | Stainless steel, black PVD finish |
| Compatibility | FN 509 (all factory internals, barrel, recoil spring) |
| Finish | Black PVD (Physical Vapor Deposition) |
| Weight | Approx. 6.2 oz (stripped, per manufacturer specs) |
| Condition | New – stripped (no barrel, no internals) |
Key Features
- RMR Slide Cut – Why it matters: You can mount a Trijicon RMR or similar footprint red dot directly to the slide without an adapter plate, keeping the optic low and the co-witness natural.
- Factory Internals Compatibility – Why it matters: No need to buy a whole new parts kit. Pull your firing pin, extractor, and spring from your factory slide, drop them in, and you’re running.
- Suppressor-Height Sights Installed – Why it matters: If you run a red dot, these black-on-black sights let you co-witness through the window. If you don’t, they still give you a taller, easier-to-acquire sight picture.
- Choice of Serration Pattern (Classic or Lightning Bolt) – Why it matters: Pick the look and grip you prefer. Lightning Bolt gives you extra texture for press checks; Classic is clean and traditional.
- Ports Matched to Apex Ported Barrel – Why it matters: If you pair this slide with the Apex ported barrel, the ports align for controlled gas escape, reducing muzzle rise and follow-up shot time.
Who It’s For
This slide is for the FN 509 owner who wants to stretch their pistol out for competition, range work, or home defense without buying a whole new gun. It’s also for shooters who plan to run a red dot and want a factory-fit, drop-in solution. If you already own an FN 509 and are comfortable swapping your own internals, this is a direct upgrade path.
Pros & Cons
- Pro: Direct RMR cut – no plate, no extra height, no extra cost.
- Pro: Black PVD finish is tough and low-glare.
- Pro: Suppressor-height sights come installed and zeroed from Apex.
- Con: Stripped slide means you must reuse your factory internals or buy a separate parts kit – an extra step for new builders.
Comparison
| Feature | Apex 5.00” Slide | Zev Technologies FN 509 Slide | Agency Arms FN 509 Slide |
|---|---|---|---|
| Price | $400 | $475–$525 | $500+ |
| Optic Cut | RMR direct (no plate) | RMR direct (no plate) | RMR direct (no plate) |
| Sights Included | Yes, suppressor-height black-on-black | No (sold separately) | No (sold separately) |
| Finish | Black PVD | Black nitride or DLC | Black nitride or DLC |
| Porting | Ports aligned with Apex ported barrel | No porting | No porting |
| Warranty | Lifetime (per manufacturer) | Limited lifetime | Limited lifetime |
Note: Zev and Agency slides are premium options but cost more and usually ship without sights. The Apex slide gives you a complete package at a lower price point.
FAQ
Will this slide fit my FN 509 Compact?
No. This slide is designed for the full-size FN 509. It will not fit the Compact or Subcompact models without significant modification. Stick with the full-size frame.
Do I need a special barrel for this slide?
Any standard FN 509 barrel will work. If you want to use the ported slide cutouts, you’ll need the Apex ported barrel – the ports are matched for that specific barrel. Otherwise, a standard barrel functions fine.
Can I use my factory FN 509 sights?
No. The Apex slide comes with suppressor-height sights already installed. Factory sights will not fit the dovetail or the height needed for co-witness with a red dot.
Is the RMR cut compatible with Holosun optics?
Yes, any optic that uses the Trijicon RMR footprint (e.g., Holosun 507C, 508T, 509T with adapter plate) will mount directly. Double-check your optic’s footprint before ordering.
Ready to Upgrade Your FN 509?
This Apex 5.00” slide gives you a longer sight radius, an RMR cut, and a tough PVD finish – all for $400. It’s a straightforward swap if you’re comfortable with basic pistol assembly. If you have questions, stop by the shop or give us a call.
✔ Nationwide delivery (all 50 states)
✔ Ships 1–2 business days
✔ 30-day returns
✔ Secure checkout
Browse more slides: FN 509 Slides | Apex Tactical
Last updated: April 2026