For Holoson – Apex Optic Mount Screw Set for FN MRD Pistols with an Apex mount for RMR Footprint Optics

For Holoson – Apex Optic Mount Screw Set for FN MRD Pistols with an Apex Mount for RMR Footprint Optics

This screw set is built to secure your Holosun red dot to an Apex mount on FN MRD pistols using the RMR footprint. At $20, it’s a budget-smart fix that saves you from buying a whole new mounting kit—just the right screws for the job. Per Apex specs, these fasteners are hardened steel, so they won’t strip under normal torque.

Manufacturer	Apex Tactical (compatible with Holosun)
Model	Optic Mount Screw Set for FN MRD
Material	Hardened steel, black oxide finish (per manufacturer specs)
Compatibility	FN 509/509T/509M, FN 502, FN 545, FN 510 — with Apex mount for RMR footprint; Holosun 407C/507C/508T/509T, Trijicon RMR
Finish	Black oxide
Weight	0.1 oz (approx. per screw)
Condition	New

Key Features

• Direct fit for Apex mounts: These screws match the thread pitch and length Apex uses on their FN MRD adapter plates. No filing, no shims—just drop in and torque.
• Hardened steel construction: Won’t stretch or snap under the 15 in-lb torque spec. That means your zero stays put round after round.
• Black oxide finish: Resists rust and cuts glare. Keeps your optic setup looking clean on a duty or carry gun.
• Cost-effective alternative: At $20, it’s a fraction of the price of a whole new mount or a gunsmith visit. You keep your existing Apex mount and Holosun, just add screws.
• RMR footprint universal: Works with any Holosun that uses the RMR pattern (407C, 507C, 508T, 509T), plus Trijicon RMR. One set covers multiple optics.

Who It’s For

If you own an FN MRD pistol (509, 502, 545, 510) with an Apex mount and want to run a Holosun dot without buying a new plate, this screw set is for you. It’s also ideal for first-time optic buyers who already have the Apex mount and need the right hardware without overspending. Budget shooters who’d rather spend $20 on ammo than on a whole mounting kit will appreciate the value.

Pros & Cons

• Pros: Affordable, exact fit for Apex mounts, hardened steel won’t strip, works with multiple Holosun models, black oxide resists corrosion.
• Cons: Only fits Apex mounts, not other brands. If you’re using a CHPWS or Springer Precision plate, you’ll need their screws. Also, no thread locker included—pick up blue Loctite separately.

Comparison vs. Alternatives

Feature	This Set ($20)	Zev Technologies Screw Set ($15)	Agency Arms Screw Set ($25)
Compatibility	FN MRD + Apex mount only	Glock MOS + Zev mount only	Glock/1911 + Agency mount only
Material	Hardened steel	Stainless steel	Hardened steel
Finish	Black oxide	Silver (uncoated)	Nitride
Price per set	$20	$15	$25
Includes thread locker?	No	No	Yes (vibratite)

Zev’s set is cheaper but doesn’t fit FN pistols. Agency’s set costs more and adds thread locker, but again, not for FN MRD. If you’re sticking with an Apex mount on your FN, this set is the only direct option at this price point.

FAQ

Will these screws work with a Trijicon RMR on my FN 509?

Yes, the RMR footprint is identical. These screws fit both Holosun and Trijicon RMR optics when used with an Apex mount on FN MRD pistols.

Do I need to use thread locker with these screws?

Yes. Apex recommends blue Loctite (242) on the threads. The screws are bare steel, so thread locker prevents vibration from loosening your zero.

Can I use these screws with a stock FN slide (no Apex mount)?

No. These screws are specifically designed for Apex’s aftermarket mount. Stock FN slides use different screws and mounting patterns. Check your setup before ordering.

Are these screws longer than the ones that came with my Holosun?

They are the correct length for the Apex mount, which is slightly thicker than a direct slide cut. If you try to use Holosun’s screws, they’ll be too short. This set solves that.

How many screws come in the set?

Four screws—enough for one optic mount. Two are for the optic-to-plate, and two are for the plate-to-slide (though the latter may vary by FN model).

Trust & Delivery

• ✅ Nationwide delivery (all 50 states)
• ✅ Ships 1-2 business days
• ✅ 30-day returns
• ✅ Secure checkout

Last updated: April 2026

Browse more in FN Optics | Optic Mounts | Holosun Accessories