5 Common FN 509 Problems You Must Be Aware of

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I had the chance to test out the FN 509 and let me tell you, while it’s a solid piece, I did face some problems with this firearm as well, so let’s talk about it.

I’ve encountered a handful of FN 509 Problems that seem pretty common among users. We’re looking at striker issues, problems with the firing pin, the occasional failure to fire, some accuracy issues concerning the factory sights, and yeah, even the slide isn’t immune to some problems. 

So, what’s the aim here? Simple. I want to break down these issues, tell you why they happen, and give you practical solutions so you can get the most out of your FN 509. 

Overview of the Problems & their Solutions

FN 509 ProblemsSolutions
Striker IssueReplace the worn-out striker assembly.
Problem with the Firing PinClean and replace the firing pin if worn.
Failure to FireReplace the weak hammer spring.
Accuracy IssueInstall new, more accurate aftermarket sights.
Problem with the SlideClean and lubricate the slide and rails.

Top 5 FN 509 Problems & Solutions

1. Striker Issue

Ah, the striker issue. During my time at the range, I noticed that sometimes the gun wouldn’t fire despite the trigger pull. 

So, after ensuring safety protocols, I disassembled the gun to get a good look at the striker. To my surprise, it seemed worn out and didn’t have that “snap” you’d expect from a well-functioning striker assembly. 

This isn’t just annoying; it’s also a safety concern that can affect your overall shooting experience.


I’m not one to give up easily, so I started researching ways to resolve this issue. First off, you’ve got to make sure your gun is unloaded and safe. 

Take out the striker assembly and inspect it for any obvious signs of wear or damage. If it’s bad, replace it; strikers aren’t overly expensive. 

I installed a new striker, and boom, the issue was gone. If you’re uncomfortable doing it yourself, a gunsmith can help you. It’s a straightforward fix that’ll make a world of difference. 

2. Problem with the Firing Pin

So, let’s dive into another problem I ran into—the firing pin. When I pulled the trigger, sometimes there was a misfire. Not cool, right? This got me puzzled and concerned. 

A misfire could mess up your aim or even be a safety risk. So, naturally, I inspected the firing pin. What I found was some wear and tear, along with debris build-up. 

It’s like the firing pin was getting stuck and not hitting the primer hard enough. These kinds of issues can sneak up on you and can’t be ignored.


Now, for the part you’ve been waiting for—the fix. After ensuring the gun was unloaded and safe, I disassembled it to reach the firing pin. 

First things first, I cleaned it up thoroughly. Then, I looked for any signs of physical damage. My firing pin was worn down, so I replaced it. Reassembled everything and went back to the range. 

If this sounds too technical, don’t sweat it. A gunsmith can sort this out for you, no fuss. 

3. Failure To Fire

Let’s get into another problem that frustrated me during my range sessions—failure to fire. You’ve got your FN 509, you’re lined up, you pull the trigger, and… nothing. 

Now, a failure to fire can stem from a variety of issues, such as bad ammo, but I was using quality rounds. So, after ensuring the firearm was safe, I took a closer look. 

The extractor was fine, and the ammo was good, so it really puzzled me for a while.


Alright, it’s time to tackle this annoying issue. After checking the ammo and confirming that it wasn’t the problem, I started inspecting other potential culprits. 

The hammer spring caught my attention. It seemed weak, not providing enough force to ignite the primer. Swapping out the weak spring for a new one made all the difference. 

The failure-to-fire issues were gone once the new spring was in place, and the gun performed flawlessly. If you’re not handy with firearms, a quick trip to the gunsmith will solve this issue. 

A new hammer spring isn’t expensive, and the labor shouldn’t cost much. A simple fix for a problem that can throw off your whole shooting experience.

4. Accuracy Issue with the Factory Sights

Let’s chat about another thorn in my side—the factory sights on the FN 509. I’ve got decent aim, but with this gun, I was missing more than hitting, and it was driving me nuts. 

The factory sights were not aligned as accurately as I’d like. 

When your sights are off, it doesn’t matter how good your aim is; you’re gonna miss, and that’s a problem.


I wasn’t gonna let bad sights ruin my day. First, I double-checked to see if the sights were securely attached. They were, but they still weren’t accurate. 

So, I decided it was time for an upgrade. There are many aftermarket sights available that are compatible with the FN 509. 

After researching, I chose one with good durability and accuracy reviews. I switched out the factory sights, and after that, it was like shooting a different gun. 

My shots were landing where I wanted them to. If you’re not up for doing this yourself, any qualified gunsmith can help you out. And trust me, it’s a game-changer.

5. Problem with the Slide

Last on the list, but certainly not least, is an issue I had with the slide. During shooting sessions, I noticed the slide wasn’t as smooth as it should be. 

Sometimes, it wouldn’t return to battery fully, and other times, it seemed to “stick” a bit when pulling it back. It’s not the kind of thing you want to experience when you’re focusing on your target. 

This can mess with the timing of your shots and, more importantly, could be a real safety concern. Trust me, it’s irritating and can mess up your whole rhythm.


Here’s how I got this sorted. First, I made sure the gun was safe and empty. I then field-stripped it to get a good look at the slide and the rails. 

I noticed some debris and a lack of proper lubrication. So, a good cleaning was the first step—remove the gunk and apply a thin layer of quality gun lubricant on the slide and rails. Also, I inspected the recoil spring to see if it needed replacing. 

It looked good, so there was no need there. After the cleanup and lubrication, the slide action improved significantly. If you’re not confident doing this yourself, take it to a gunsmith.

Final Verdict

Alright, let’s wrap things up. The FN 509 is a reliable gun, but like all mechanical things, it’s not without its challenges. 

I’ve tested this piece thoroughly, and yes, I’ve faced issues like striker problems, firing pin wear, failure to fire, issues with factory sights, and even slide hitches. But the good news is every single issue is fixable. 

From swapping out worn strikers to getting new sights, these are practical solutions that will get you back on the range in no time. 

Safety should always be your priority; if you’re not comfortable tackling these issues yourself, a qualified gunsmith can sort things out for you. 


Is the FN 509 drop safe?

Yes, the FN 509 features a drop-safe trigger, adding an extra layer of safety.

Is FN 509 better than Glock?

The FN 509 has higher quality in some areas, but the Glock Gen 5 frame may offer better ergonomics up close.

What is the FN 509 cut for?

The FN 509 slide can be machined and installed with an RMR pattern optic.

What is the difference between FN 509 and tactical?

The primary difference is that the FN 509 Tactical features a threaded, extended barrel and is milled for use with a reflex optic adapter plate.

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I'm Micheal, an avid shooter and hunting enthusiast from Texas. I'm a recreational shooter who loves to spend time at the range and enjoy learning about new firearms and gears. I love to write about guns and share my passion for shooting with others.

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