Apex Optic Mount for ACRO/MPS* – FN MRD

Description

The Apex Optic Mount for ACRO/MPS on FN MRD-pattern slides is a direct-fit solution for owners of the FN 509 series and FN 545 who want to run a red dot without the hassle of stacking adapter plates. Machined from a single billet of steel and finished with a durable black oxide coating, this mount is built to hold zero under heavy use. It integrates directly with the FN Low Profile Optics Mounting System™, meaning you don’t need the factory MRD insert or any extra spacers. The mount’s integrated locking key engages the slide cut directly, giving you a solid, repeatable interface that simplifies installation and keeps your optic secure.

Compatible optics include:

• Aimpoint® Acro™ P-1 and P-2
• Steiner MPS
• Lead & Steel Pandora PB-3
• Any optic with an “ACRO” footprint

Key specs and fitment notes:

• Designed specifically for FN 509 and FN 545 slides with the FN Low Profile Optics Mounting System™
• Billet steel construction with black oxide finish resists corrosion and wear
• Mounts directly to the factory slide — no MRD insert needed, no stacking plates
• Integrated locking key interfaces with the slide’s mounting system for a precise fit
• Retains factory iron sight co-witness potential (depending on optic height)

For shooters using the Steiner MPS, we recommend pairing this mount with the Apex Super Clamp to expand the clamping range and ensure a tight, repeatable grip on the optic body. This is especially useful if you plan to swap optics or want extra peace of mind during hard use. The mount itself is low-profile and keeps the optic close to the bore axis, which helps with recoil management and target re-acquisition.

California gun owners appreciate that this mount adds no bulk to the slide and works with standard-height iron sights for those running a co-witness setup. It’s a practical upgrade for FN 509 and FN 545 owners who want a reliable, plate-free optic mount that installs in minutes and maintains factory slide integrity. At a $60 price point, it’s a cost-effective way to run a closed-emitter optic like the Acro or MPS without proprietary plates or extra hardware. If you have questions about compatibility with your specific FN model or California roster considerations, our team at Calguns Depot is familiar with the nuances of state law and can help you confirm fitment before purchase.