Best Fn 509 Tactical Red Dot Sights

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I’ve hands-on tested a variety of handguns and accessories, including the FN 509 Tactical. So, what’s the fuss about the FN 509 Tactical? Well, it’s a gem of a gun, no doubt. 

But a gun is only as good as its accessories, right? That’s why I’ve spent considerable time finding the perfect red dot, and the Trijicon SRO emerged as my top choice. 

In this article, I’m diving deep into the realm of red dot sights that best complement the FN 509 Tactical. I’ve tested them for durability, precision, ease of use, and how well they pair with the FN 509 Tactical. 

If you are in a hurry I have mentioned below my top picks and what they offer you

  • Trijicon SRO (Best Durable and Accurate)
  • Vortex Optics Venom (Best budget – Friendly RDS)
  • HOLOSUN HS507C X2 (Best for Battery Life)
  • Leupold DeltaPoint Pro (Best Value)
  • Vortex Optics Viper (Best Affordable Red dot sight)

Top 5 Best Red dot For Fn 509 Tactical

Table showing the Best fn 509 tactical red dot sights with a quick comparison table listing all their key features.

ProductKey FeaturesRating
Trijicon SROParallax free design
Aluminum housing
30000 hours battery life
Top loading battery compartment
Vortex Optics VenomAluminum housing
10 brightness levels
Automatic plus manual brightness mode
30000 hours battery life
HOLOSUN HS507C X2Solar failsafe tech
Shake awake
Lock mode
50000 hours of battery life
Leupold DeltaPoint ProTop loading battery compartment
Aluminum housing
Great lowlight performance
Vortex Optics Viper6 moa dot
Low profile
Multicoated lens
Water and dust protection

 1. Trijicon SRO – Most Durable and Accurate


Brand: Trijicon | Material: Aluminum | Dimensions (L*W*H): 2.2 x 1.3 x 1.4 in. / 55 x 32 x 34mm

What’s So Special?

  • Fast target acquisition
  • Accuracy and durability
  • 3 years of continuous use

The Trijicon SRO shines bright in a sea of red dot sights. Built from rugged aluminum, this sight is a beast when it comes to durability. 

The lens offers fast target acquisition, and its parallax-free design keeps your aim steady even if you’re moving around. You’re getting a broader field of view, too, which is a godsend in high-stakes situations. 

And listen to this: the battery life is a game-changer—three years without a hitch.

Why to Buy: You’re in for a treat with the Trijicon SRO. First off, its accuracy is second to none. You can easily spot and acquire targets, making your shooting game top-notch.

Durability? It’s got that in spades, thanks to the aluminum construction. You’re not going to worry about the sight faltering when you need it the most. 

The battery life is another big plus. Three years of constant use? Yes, please! Switching batteries is a cinch, too, with its user-friendly top-loading system.

Why Not to Buy: Alright, let’s talk about the drawbacks. The most glaring one is the price tag. It’s not for those looking to save a few bucks. 

The sight’s high-performance features come with a cost. Also, it’s so feature-rich that it might be overkill for casual users. 

Who Should Buy: So, who’s this gem for? If you’re someone who takes shooting seriously, whether for combat situations or competitive sports, the Trijicon SRO is right up your alley. 

Its unmatched durability and accuracy make it a perfect fit for military use, especially when paired with the FN 509 Tactical. 

Even for everyday carry, if you can stomach the price, this sight will not disappoint. It’s built to endure and perform, meeting the highest of expectations.

My Testing

I mounted this bad boy on my FN 509 Tactical and took it out for a spin. Let me tell you, it felt like these two were made for each other. 

The sight held zero perfectly, even after some tough handling. In poor light conditions, the auto-brightness settings came to the rescue. 

Accuracy was pinpoint, making each shot feel rewarding. All in all, the Trijicon SRO transformed my shooting experience for the better.


  • Best for combat shooting
  • Exceptionally durable
  • Crisp dot enhances accuracy
  • Wide field of view


  • Pricier than other options

2. Vortex Optics Venom – Best Budget Friendly


Brand: Vortex | Material: Aluminum | Dimensions (L*W*H): 6.1 x 4.8 x 2.1 inches

Why Is This The 1st Runner Up?

  • Similar features like Trijicon SRO
  • Half the price of Trijicon SRO
  • 30000 hours of battery life

Here’s the scoop on the Vortex Venom. It’s made of durable aluminum.

Much like the Trijicon SRO, it boasts excellent durability, thanks to that sturdy aluminum housing. You get ten brightness levels and a crisp 3 MOA red dot that stays sharp to the edges. 

Best of all, this sight offers a jaw-dropping 30,000 hours of battery life. And hey, changing batteries? It’s a snap with the top-loading system.

Why to Buy: So you’re asking, why go for the Vortex Venom? Listen, if you’re after similar features to the Trijicon SRO, but your wallet is saying, “slow down,” this is your go-to. 

Plus, you get a plethora of brightness levels and a no-nonsense 3 MOA dot. Battery life? An astounding 30,000 hours. Oh, and swapping out those batteries is easier than tying your shoes.

Why Not to Buy: Okay, it’s not all sunshine and rainbows. First off, it lacks night vision compatibility, which could be a deal-breaker for some. Also, if you’re a die-hard fan of premium brands like Trijicon, this might feel like a step-down. 

Lastly, while it’s durable and reliable, it’s not quite at the Trijicon level of toughness. So, if you’re planning to put this through the wringer in extreme conditions, you might want to think twice.

Who Should Buy: So, who’s this for? If you’re after quality but are on a budget, this one’s calling your name. It’s 

also excellent for those new to red dot sights, as it offers a balance of features without overwhelming you. 

In short, if you want a blend of durability, functionality, and affordability, this sight should be on your shortlist.

My Testing

Now, here’s where the rubber meets the road. I slapped the Vortex Venom on my FN 509 Tactical and took it to the field. Man, was I surprised! 

The sight held up beautifully, maintaining zero and delivering precise shots. In less-than-ideal lighting, the various brightness settings were a lifesaver. While it’s not a Trijicon, it felt close enough, especially considering the price difference.


  • Easy installation
  • Lightweight
  • Simple battery change
  • Budget-friendly


  • No support for night vision

3. Holosun HS507C X2 – Excellent Battery Features


Brand: Holosun | Material: Aluminum | Dimensions (L*W*H): 5 x 4 x 4 inches

What You’ll Love About It?

  • Exceptional battery life with 50000 hours of continuous run
  • Durable
  • Maximum light transmission

So here’s the deal with the Holosun HS507C X2. It’s got it where it counts. Crafted from durable aluminum and sized at 5 x 4 x 4 inches, this red dot sight boasts an astonishing 50,000-hour battery life. 

Thanks to its solar failsafe and shake-awake features, the battery life stretches even further. But that’s not all! With multilayer glass coatings, it maximizes light transmission, giving you a super-clear sight picture.

Why to Buy: Are you planning on long hunting trips? Then listen up! With a jaw-dropping 50,000-hour battery life, you won’t be left in the lurch. 

The solar failsafe kicks in when the battery is low, ensuring the sight never powers off. It’s also IPX-7 rated, meaning it’s practically waterproof. 

And who doesn’t want a sight that can survive a quick dip? Add to that the user-friendly lock mode, and you’ve got yourself a pretty reliable and convenient setup.

Why Not to Buy: But hey, it’s not all sunshine and rainbows. The build isn’t as rugged as some competitors, so if you’re rough on your gear, be warned. 

Who Should Buy: If battery life sits at the top of your wishlist, then Holosun HS507C X2 should be your go-to. It is ideal for folks who like spending long hours in the field or those who despise frequent battery changes. 

Its multilayer glass coating makes it great for any lighting condition. And hey, if you own an FN 509 Tactical and want something sleek yet functional, look no further.

My Testing

Alright, real talk. I took this baby for a spin with my FN 509 Tactical, and man, it delivered. The 50,000-hour battery life is no joke. 

The sight held up well, even in varied lighting conditions. The lock mode also came in handy, preventing any accidental setting changes. Trust me, this sight delivers more than it promises.


  • Exceptional battery life
  • User-friendly features
  • Great for the budget
  • Compact and sleek design


  • Not rugged enough

4. Leupold DeltaPoint Pro – Best Value


Brand: Leupold | Material: Aluminum | Dimensions (L*W*H): 4 x 6 x 3.37 inches

What About It?

  • Convenience with precision
  • Easy brightness adjustment
  • Well-built

The Leupold DeltaPoint Pro Reflex Sight is all about balance. Made in the USA, its aluminum frame measures a solid 4 x 6 x 3.37 inches. 

The top-loading battery compartment is genius, allowing you to swap batteries without losing zero. The easy-to-adjust brightness settings make sure your reticle is always visible, no matter the lighting. What’s not to love?

Why to Buy: Why go for Leupold DeltaPoint Pro? Let’s chat. First, the battery compartment on top is a game-changer. 

There is no need to remove the sight to replace batteries. It keeps your zero intact, and that’s huge. Secondly, this sight is built to last with its sturdy aluminum frame. 

Third, it’s got excellent brightness adjustments that adapt well to any environment. Fourth, it supports night vision. Yeah, you heard right.

Why Not to Buy: Now, it’s not all perfect. Price could be a stumbling block for some folks. There are less pricey 

alternatives out there offering the same features. 

So, if you’re counting your pennies, this may not be the most budget-friendly option. Sure, it’s a high-quality sight, but the price tag might make you pause and consider other options.

Who Should Buy: So, who’s the perfect match for this sight? If you’re a person who craves a durable, precise, and convenient optic, this is it. And if you’re into night-time shooting? Even better, it supports night vision. 

This sight suits all—from casual shooters to law enforcement. Don’t fret over the price if you’re after quality and performance; the DeltaPoint Pro delivers.

My Testing

Time to get personal. I attached the DeltaPoint Pro to my FN 509 Tactical and went shooting. The sight delivered on every promise. 

Brightness adjustments? On point. Ease of battery replacement? Flawless. I even switched the batteries in the field, and guess what? Zero held steady. 

For its price, I expected a lot, and it met those expectations.


  • Top-loading battery compartment
  • User-friendly
  • Supports night vision
  • Lightweight
  • High build quality


  • Overpriced compared to similar options

5. Vortex Optics Viper – Best Affordable Red dot sight


Brand: Vortex | Material: Aluminum | Dimensions (L*W*H): 4.5 x 5.4 x 2.3 inches

Last but not the least

Meet the Vortex Viper: compact, affordable, and no-nonsense. 

It sports a low-profile design, ideal for the FN 509 Tactical. Multilayer coatings on the lens keep dust and glare at bay, providing a clear field of view. 

Trust me, for its price, it’s quite the steal.

Why to Buy: Look, if you’re on a budget but don’t want to skimp on quality, the Vortex Viper is your guy. Its low-profile design makes it a snug fit on your FN 509 Tactical.

Plus, the multilayer lens coatings ensure a clean sight picture, free of annoying dust or glare. Let’s not forget it’s more pocket-friendly compared to some high-end models but still offers solid accuracy.

Why Not to Buy: Now, here’s the catch. Battery features aren’t the Viper’s strong suit. So, if you’re planning extended shooting sessions, you might be disappointed. 

Also, if you’re someone who’s all about the extra features, this sight may seem a bit too basic for your taste. But again, remember the price point.

Who Should Buy: The Vortex Viper is a perfect fit for the budget-conscious shooter who doesn’t want to compromise on essential features.

If you own an FN 509 Tactical and desire a low-profile, unobtrusive sight, this is it. It’s light, efficient, and won’t break the bank. 

The Viper caters to both newbies and seasoned shooters looking for a solid yet affordable option.

My Testing

Here comes the real talk. I paired the Viper with my FN 509 Tactical and hit the range. The low-profile design? Spot-on. 

My field of view was clear, just as advertised. Yes, the battery life is not jaw-dropping, but it gets the job done. For a budget sight, the Vortex Viper held its own.


  • Affordable
  • Low-profile design
  • Clear field-of-view thanks to multilayer lens coatings


  • Lackluster battery features

Things To Keep In Mind While Purchasing A Red Dot Sight

Money and time are the two resources that you’d never want to end up wasting over useless products, so save yourself the misery and keep these things in mind when you’re out in the market looking for the best red dot sight for FN 509 Tactical pistol.


A durable red dot sight that can bear pressure or attack is the one you need to mount with your Fn 509, which is considered best for combat. Go for the ones with aluminum housing and a rugged exterior. All 5 products mentioned above offer this feature. Still, Leupold DeltaPoint Pro Reflex Sight and Trijicon SRO Red Dot take the trophy.

Battery Features

Trust me. The most annoying thing would be if you just picked up your red dot sight and were ready to shoot when you realize you’re out of battery. Or if you have to take up the fatigue of removing the sight while changing the batteries and end up losing zero. That is why a red dot sight with the best battery features is really important. I’d suggest you choose HOLOSUN HS507C X2 Solar Failsafe when it comes to the battery features.

Buy Once Cry Once!

It would be best if you went for a sight that isn’t so heavy on your pocket while matching the requirements of the best suitable red dot sight for your fn 509. If you want to go for a more budget-friendly sight, then Vortex Venom Red Dot is the best pick for you, while if you are someone like me who likes to invest in an extraordinary product once and cherish the experience for years to come, based on durability and efficiency, then you must go after the no.1 pick in this list – Trijicon SRO fn 509 tactical red dot

Zero Retention

When the sight is removed and reattached to the pistol or rifle (to change the batteries or so), most red dot sights fail to hold their zero, so you need to choose the sight that has good zero- retention or doesn’t require removal or sight for the sake of battery changing, so you don’t have to compromise on the accuracy and precision in target acquisition – like Trijicon SRO Red Dot, Vortex Venom Red Dot, and Leupold DeltaPoint Pro micro Reflex Sight.

Low Profile

There is a great demand for low-profile red dot sights that are easily mounted and look good on the pistol without adding extra weight to the host firearm. Your FN 509 needs exactly this, so pick the compact red dot sight like both Vortex sights and Trijicon SRO sight.


Alright, we’ve delved into the realm of red dot sights and tested them on the FN 509 Tactical, and the winner is the Trijicon SRO. You might wonder why. Well, let’s recap.

The FN 509 Tactical is a stellar gun. However, to unlock its full potential, you need a red dot sight that isn’t just good but exceptional.

Remember, your choice should sync with your individual needs and preferences. But for a well-rounded experience, the Trijicon SRO ticked most boxes.   

It complements the FN 509 Tactical, not just as a useful tool but as an extension of the firearm itself.

So there you have it, folks. My top pick is the Trijicon SRO, but the right sight for you could be different based on what you’re looking for. Go ahead, make your pick!


What red dot fits the FN 509?

The Trijicon SRO is my top choice for the FN 509 Tactical, offering a well-rounded performance.

Is FN 509 better than Glock?

The FN 509 offers higher quality and feels more robust than the Glock, particularly when compared at a distance.

How accurate is the FN 509 tactical?

The FN 509 Tactical is extremely accurate, and any discrepancies in short-range groups are usually due to shooter error.

How many rounds does it take to break in FN 509?

The typical break-in period for the FN 509 is between 200-300 rounds, with most issues diagnosed within the first 2-4 magazines.

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I quit my job as a high-powered lawyer to pursue the outdoors. I spend most of my time fishing and hunting but am also an avid shooter with two years experience writing about firearms related topics.

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