Table of Contents
The FN 509, developed by FN Herstal, is a striker-fired 9mm handgun introduced in 2017 as a duty-ready pistol designed for self-defense, law enforcement, and military use. Featuring a 4-inch barrel, 17+1 round capacity, and an ergonomic polymer frame, the FN 509 is built for reliability, accuracy, and durability. Its aggressive grip texture, ambidextrous controls, and optics-ready models make it a strong contender in the modern handgun market.
That being said, even a well-engineered pistol like the FN 509 isn’t without its flaws. Many shooters, including myself, have encountered trigger stiffness, failure to feed, and a stiff magazine release, which can impact handling and overall performance.
In this article, I’ll break down the most common FN 509 problems and provide practical solutions to keep your pistol functioning at its best. By the end, you'll know how to fix these issues and whether the FN 509 is the right handgun for you. Let’s get started.
Meet FN 509: Main Specs & Problems Outlined
The FN 509 is a compact, striker-fired handgun designed for duty use, personal defense, and tactical applications. The FN 509 features a 4-inch barrel, is chambered in 9mm, and offers a standard 17+1 round magazine capacity (with extended options available). Built with a polymer frame and a stainless-steel slide, it balances durability with a lightweight feel. The FN 509 comes equipped with fixed three-dot sights, though FN offers optics-ready models for those who prefer red dot compatibility. The aggressive grip texture and ambidextrous controls make it adaptable for a wide range of shooters.
Wanna learn more about the main features of the FN 509? Check out our FN 509 review and see why it’s a solid contender for everyday carry and tactical use.
Now, let’s shift attention to the most common FN 509 problems. From my experience and reports from other shooters, certain issues tend to stand out. The most frequently mentioned concerns include trigger stiffness, slide stop malfunctions, failure to feed, accuracy inconsistencies, and magazine release stiffness. Now, let’s jump right into a detailed look at the most troublesome FN 509 issues and how they can be easily solved.
FN 509 Problems: FN 509 trigger stiffness issue and how to fix it
One of the most frequent FN 509 problems is its trigger stiffness. I’ve personally experienced that the trigger pull feels heavier than expected, especially for a modern striker-fired handgun. FN lists the trigger pull weight at approximately 5.5 to 7.5 pounds, which is noticeably heavier compared to competitors like the Glock 19 or the SIG P320.
This issue stems from FN’s factory-set trigger design, which prioritizes safety and durability over a lighter, crisper break. As a result, some shooters find it difficult to achieve smooth, rapid follow-up shots, particularly during high-stress scenarios. The stiffness is even more noticeable during the initial break-in period, as the internals require repeated use before any significant improvement in feel. For those accustomed to lighter, more responsive triggers, the FN 509’s heavier pull can negatively impact accuracy and overall shooting experience.
How to solve FN 509 trigger stiffness problem
To address the FN 509's trigger stiffness problem, here’s what you can do.
- Break-In Period: Regularly dry-fire the pistol and conduct live-fire sessions to allow internal components to wear in naturally, which can lead to a smoother trigger pull over time.
- Professional Gunsmithing: Consult a qualified gunsmith to perform a trigger job, which may involve polishing internal parts or adjusting spring tensions to achieve a lighter, crisper trigger pull.
- Aftermarket Trigger Kits: Explore reputable aftermarket trigger kits designed specifically for the FN 509. These kits can offer reduced pull weight and improved trigger feel.
For a detailed walkthrough on addressing this specific issue, this Reddit thread offers practical tips and solutions.
FN 509 Problems: FN 509 failure to feed issue and how to fix it
One of the most common FN 509 problems is failure to feed, an issue that I’ve encountered personally. This problem occurs when a round fails to properly chamber, causing a stoppage that requires immediate clearing before the pistol can fire again. The primary cause of failure to feed in the FN 509 is often related to magazine tension and feed lip design, which can create inconsistencies in round positioning.Some users report that the issue is more pronounced with certain ammunition types, particularly with rounds that have a flat-nose or irregular bullet profile. Additionally, a stiff recoil spring can sometimes cause sluggish cycling, preventing the next round from chambering smoothly. For those relying on the FN 509 for self-defense or duty use, an unreliable feed can be a serious concern, making it essential to identify and address the root cause.
How to solve FN 509 failure to feed problem
To address the FN 509's failure to feed (FTF) problem, use the methods below.
- Magazine Inspection and Maintenance: Regularly clean and inspect your magazines for debris, damage, or wear. Ensure the feed lips are not bent or cracked, as this can impede proper cartridge alignment.
- Ammunition Selection: Use high-quality, factory-loaded ammunition with round-nose bullets, which are more likely to feed reliably. Avoid using reloads or ammunition with irregular bullet profiles that may cause feeding issues.
- Recoil Spring Assessment: Check the recoil spring for signs of wear or damage. A weakened or overly stiff recoil spring can disrupt the slide's cycling, leading to FTF issues. Replacing it with a factory-standard spring can restore proper function.
- Chamber and Feed Ramp Cleaning: Thoroughly clean the chamber and feed ramp to remove any carbon buildup or debris that could hinder smooth feeding. Polishing the feed ramp with a mild abrasive can also enhance cartridge movement into the chamber.
For a detailed walkthrough on addressing this specific issue, the FN Forum offers practical tips and solutions.
FN 509 Problems: FN 509 magazine release stiffness issue and how to fix it
One of the most frustrating FN 509 problems is its stiff magazine release, which many shooters have noticed during reloads. This issue is particularly problematic for those who rely on fast magazine changes, as it requires excessive force to eject the mag, slowing down reload times.
The primary cause of this problem is FN’s tight magazine catch design, which ensures a secure hold but makes operation difficult, especially when the pistol is new. Additionally, the strong magazine spring tension can add resistance, making it even harder to drop a fully loaded magazine. I have also noticed that the ambidextrous magazine release can feel inconsistent, with one side requiring more pressure than the other.
For those using the FN 509 for self-defense or competition, a stiff magazine release can hinder efficiency and make reloads unnecessarily difficult under pressure.
How to solve FN 509 magazine release stiffness problem
To address the FN 509's magazine release stiffness problem, consider the following steps.
- Break-In Period: Regularly operate the magazine release during initial handling sessions to naturally wear down tight components, easing operation over time.
- Lubrication: Apply a small amount of firearm-specific lubricant to the magazine catch mechanism to reduce friction and facilitate smoother releases.
- Magazine Inspection: Ensure that magazines are properly seated and free from debris or manufacturing burrs that could impede release. Cleaning and lightly lubricating the magazine exterior can also assist in smoother insertion and ejection.
- Aftermarket Modifications: For persistent issues, consider consulting a qualified gunsmith about installing an aftermarket extended magazine release, which can provide increased leverage and easier operation.
For a detailed walkthrough on addressing this specific issue, this Reddit thread offers practical tips and solutions.
FN 509 Problems: Choosing the right FN 509 holster
Choosing the right FN 509 holster is crucial for secure, comfortable, and efficient carry. A properly fitted holster keeps your FN 509 in place while allowing for a smooth, reliable draw, whether for concealed carry, duty use, or range training.
When selecting the FN 509 holster, start by considering your intended use. IWB holsters (inside-the-waistband) are best for concealed carry, offering better concealment, while OWB holsters (outside-the-waistband) provide easier access for open carry or competition shooting. Retention is another key factor—adjustable retention holsters add extra security, while experienced shooters may prefer models designed for a quicker draw.
Carry style and materials matter as well. Appendix carry allows for fast access, while strong-side carry offers a more traditional and comfortable position. Leather holsters mold to your body over time for better comfort, whereas kydex holsters provide durability and superior firearm protection. Choosing the right FN 509 holster enhances comfort, safety, and accessibility, ensuring your pistol is secure and ready when needed.
Best FN 509 holsters by Craft Holsters
For the best FN 509 holster, Craft Holsters is the go-to choice. Their custom-fit designs provide a secure hold, while premium leather construction ensures superior retention, comfort, and quick draw. With a focus on quality and reasonable price, Craft Holsters delivers top-tier solutions for both concealed carry and tactical use.
One excellent holster for FN 509 is the FN 509 IWB Holster w Steel Clip. This inside-the-waistband (IWB) holster is crafted from premium leather, offering enhanced retention while molding to your body over time for maximum comfort. The steel clip ensures a secure attachment, making it an ideal choice for everyday concealed carry.
For those who prefer shoulder carry, the FN 509 Shoulder Holster System is a top-tier option. This custom-fit leather rig provides excellent weight distribution, reducing strain for all-day carry. The design includes a double mag pouch for extra ammunition, ensuring you're always prepared. The adjustable harness allows for a natural draw angle, improving both accessibility and security.
If you're searching for a high-quality holster for FN 509, Craft Holsters offers the best selection, ensuring a secure fit, long-term durability, and ultimate carry convenience.
Conclusion - Should I buy FN 509 despite its problems?
The FN 509, like any firearm, comes with its share of challenges. Some of the most commonly reported issues include trigger stiffness, failure to feed, and a stiff magazine release. However, none of these problems are deal-breakers. Now that you know how to fix them, the FN 509 can perform reliably with the right adjustments and maintenance. Just as important is choosing the right FN 509 holster, ensuring secure retention, comfort, and a quick draw for everyday carry or duty use.
The FN 509 is an excellent choice for self-defense, duty use, and tactical applications, offering solid ergonomics, durability, and high-capacity magazines. Its striker-fired system and aggressive grip texture make it a great fit for those who want a combat-ready 9mm handgun. However, those looking for a lighter trigger pull or a micro-compact carry option might prefer a different model.
After spending time with the FN 509, once properly broken in and set up, it proves to be a dependable, well-built handgun that’s worth considering for shooters who prioritize performance, reliability, and versatility.
