In this guide, let's check out some of the best FN 509 red dot sights on the market.

After testing so many optics in the past few years, we feel confident to honestly recommend these based on durability, mount compatibility, ability to retain zero, long battery life and price. The ones that don't work well didn't make the list.

Let's check it below:

Best FN 509 Red Dot Sights

Disclosure: All products have affiliate links for earning commission to support the website when you purchase

Top 3 Best Red Dot For FN 509

Best Overall

Holosun 507C

Best FOV

Trijicon SRO

Best For Competition

DeltaPoint Pro

Trijicon SRO - Largest FOV

red dot for fn 509 tactical

Why we picked this one - The Trijicon SRO is by far the best large window optic for the FN 509 tactical, FN 509 LS Edge, and other handguns for fast target acquisition. 

Bigger Window  - Acquire the red dot fast and consistently even if you're slightly off center. Spend no time looking for the red dot reticle or getting lost in the window during follow up shots.

Easier Battery Access - Load/Replace battery right from the top! No sight removal or re-zero required

Better Follow Up - Reacquire the red dot sight after follow-up gun shots muzzle flip without losing the red dot sight from inside the window.

Same RMR mounting footprint - Using the exact mounting footprint keeps everything compatible without having to buy special accessories.


  • Magnification: 1X
  • Reticle: 5 MOA option is the best
  • Turret Value: 1 MOA / Click
  • Field of View: Round 0.98" X 0.89"
  • Construction: 7075 T6 aluminum
  • Dimension: 2.2"X1.3"X1.4"
  • Weight: 1.6 oz
  • Battery Life: 3 - 4 years

Read Trijicon SRO Review

Holosun 507C X2 - Best Overall

fn 509 red dot sight

People love Holosun red dot optics for FN 509 - The Holosun 507C X2 does the same thing the original V2 model does but better in every way that improved the shooting experience while still remains affordable.

fn 509 optics

NEW ACSS Model - Watch the 250 MOA outer ring guides the eye back to the reticle center

Uses RMR Footprint - No special adapter or milling required! Just use the same Trijicon RMR adaptor plate that comes with the FN 509 Tactical.

Bigger Buttons - Adjustment buttons in the dark or day easily even with big fingers

Near Infinite Battery life - 50,000 hours of battery life plus solar panel backup power if the battery goes out.

Side Loading Battery - This feature eliminates the need to remove the sight for battery swap and re-zeroing. Access the battery from the side tray

Solar Power BackUp - Solar fail-safe power kicks in immediately when the battery dies, so the optic will always remain on and ready.

At this price point, which is the lowest it's ever been for a Trijicon RMR alike sight, You'll save a ton of money. Just make sure to click the button below for the best deal.


  • Magnification: 1X
  • Reticle: 1 MOA, 32 MOA ring, or combined
  • Turret Value: 1 MOA / Click
  • Field of View: 0.63" X 0.91"
  • Construction: 7075 T6 aluminum IP67 rated
  • Dimension: 1.78"X1.15"X1.15"
  • Weight: 1.5 oz
  • Battery Life: 3 - 4 years

Read Holosun 507C X2 Review

Trijicon RMR - Best Durability

what red dots fit fn 509 tactical

Trijicon RMR RM07-C-700679

Trijicon RMR is the grandfather of all modern red dot sights for pistols. This is one of the most durable red dot sights made ever for duty use on your FN 509 tactical pistol.

Tighter Battery Grip - The Type 2 model grips the CR2032 battery much tighter to prevent lose electrical contact during high G recoil

Combat Proven Durability - The forged 7075 T6 aluminum frame and body features rounded hood edges divert any point impact stress away from the glass to withstand physical abuse

Rounder Dot Appearance - 6.5 MOA red dot that gives that big center reticle without the red dot dots looking smeared when dealing with emitter glare

Slide Racking Assist - RMR is very rugged for slide racking against any hard surfaces. 


  • Magnification: 1X
  • Objective Lens: 0.9" x 0.6"
  • Eye Relief: Unlimited
  • Reticle Type: 6.5 MOA dot
  • Turret : 1 MOA / Click
  • Length: 1.8 inches
  • Weight: 1.2 oz
  • Battery: CR2032
  • Battery Life: 4 years 

Leupold DeltaPoint Pro - Large FOV Like SRO

fn 509 red dot

The DeltaPoint Pro is Leupold's best open emitter red dot sight. The field of view of this compact red dot sight is as much as a Trijicon SRO but in a rectangular shape. The FN 509 comes with an factory adapter plate and spacer to fit the DeltaPoint pro right out of the box.

Larger Window Than RMR - The field of view is so much bigger than Trijicon RMR, and the optic height is just right for most shooters

6 MOA and 2.5 MOA - 6 MOA option is much easier to see and it's a feature now available for shooters with astigmatism

Extra Lens Hood Protection - The added lens hood protects the optic from receiving direct impact that increases durability and making it fail proof.  

Easier Battery Access - No sight removal or re-zero required. This user friendly design feature has been well tested and implemented into many other new optics today.


  • Magnification: 1X
  • Objective Lens: 1.01" x 0.68"
  • Eye Relief: Unlimited
  • Reticle Type: 2.5 or 6.5 MOA
  • Turret : 1 MOA / Click
  • Dimension: 1.8" X 1.3" X 1.3"
  • Weight: 1.9 oz
  • Battery: CR2032
  • Battery Life: 1600 hours

Read more DeltaPoint Pro review

Vortex Venom - Best Value

fn 509 red dot

Why we pick this one - The Vortex Venom is an entry level red dot sight. It's not for duty use, but it's good for range use without spending over $300. 

Top-Loading Battery Access - Install the battery right from the top without the worry of removing the whole sight or having to re-zero the sight afterward

Multiple Intensity Settings - Rapid target engagement under a full range of lighting conditions

Wide Field of View - Thin lens hood frame doesn't obscure the brightness of the dot in the shooter's field of view for better sight acquisition and does not lose the brightness and accuracy of the dot.

Super Lightweight - Weighing only 1.1 oz built with rugged aluminum housing, its compact design helps for high speed shooting


  • Magnification: 1X
  • Window Size: 0.58" x 0.77"
  • Eye Relief: Unlimited
  • Reticle Type: 3 or 6 MOA
  • Turret : 1 MOA / Click
  • Dimension: 1.6" X 0.98" X 0.95"
  • Weight: 1.0 oz
  • Battery: CR2032
  • Battery Life: 3000 hours

Read Venom Review

Common FAQ

FN 509 Tactical Red Dot Compatibility

fn 509 tactical red dot compatibility

The FN Low Profile Optics Mounting System is compatible with almost all micro red dot sights on the market.

The included package contains mounting plates and screws for some of the most popular optics such as:

  • Vortex Viper, Razor, Venom
  • Docter Optic
  • Trijicon RMR, SRO
  • C-More STS2
  • Burris
  • Leupold DeltaPoint Pro

Highly recommend using the aftermarket CHPWS plates for tighter slide to plate contact surfaces.