FN developed the FN509 as an improved version of their FN FNS9. The FN 509 was developed and eventually entered into the US Army’s XM17 Modular Handgun System Competition. Originally the 509 was developed for a Solicitation started by the US Air Force. The goal of the competition was to replace the then-standard issue Beretta M9. FN lost the XM17 Modular Handgun System Competition to Sig who won with their M17 that was based on the Sig P320 series. After losing the XM17 Modular Handgun System Competition FN offered the FN509 to the civilian market.
At the time the FN509 was introduced to the civilian market there had been a large number of guns flooding into the polymer striker-fired duty gun space. At the time it was competing with the Smith & Wesson M&P, HK VP9, Springfield XD, Glock, and the Sig P320 to name a few. So the FN 509 was entering a fairly crowded market. FN had their FNS line which included 9mm and 40 caliber striker options but it wasn’t exactly considered successful on the civilian or even law enforcement market.
FN is known for making quality weapons that primarily do well in the military market, not the civilian market. So when FN introduced the FN 509 as an improved version of the FN FNS many were skeptical of how well it would do on the civilian market considering FN’s poor track record. Despite their quality designs FN rarely pushes products hard on the civilian market.
The FN SCAR and FN5.7, for example, are both designed to be manufactured extremely efficiently and when mass-produced they could be offered at a much more affordable price and own the market but instead, FN decides to release those models at relatively low volume at a premium price. FN just seemed to stop marketing the FN FNS fairly quickly so many were afraid the FN 509 would fall to the same fate.
You could describe the FN 509 as a modern duty sized handgun. It’s roughly the same size as the HK VP9, HK P30, S&W M&P Fullsize, and the Walther PPQ. With its 17 rounds capacity, it’s large enough to be a duty gun but small enough to carry concealed for most body types.
You can get optional 24 round magazines from FN if you want even more capacity although those will likely be relegated to backup magazines. They could be used if you’re carrying in an overt FN 509 OWB Holster or IWB if you have a very wide body or an oversized shirt. But I’d suggest keeping the 24 round magazines as a backup option. FN includes a sleeve with the magazine so you don’t have to worry about over inserting the magazine causing damage to the gun or magazine.
The magazines themselves you can only get then as an FN branded product, and they’re not cheap. They cost right around $45. They’re metal construction and they drop free quite easily. I haven’t seen aftermarket companies show any interest in providing options. You can also buy extensions for the magazines and you can get a 24 round magazine directly from FN. The 24 round magazine includes a sleeve so that you won’t over insert the magazine into the gun.
The magwell of the gun is chamfered on pretty much all the sides, although it’s not much this is still chamfering. The material around the grip, or at least on the sides, is very thin, so they can’t chamfer much to get a good magwell on the gun. There are two little indentations at the bottom of the sides of the grip that allow you to get in there and get more grip on the mag baseplate if you have to strip the magazine out of the gun.
Now as far as the grip and ergonomics of the gun, we’ll start with the back strap. The gun comes with two replaceable back straps, a small and a medium or a flat and a medium. FN will also sell you a large backstrap separately. The back straps themselves have these rows of texturing that are quite deep and have little rounded off knobs on the rows themselves. When you feel them just alone, they don’t feel that aggressive, but they definitely have a little bit of bite.
There is no beavertail on this gun, but it does have a decent tang and the tang of the grip itself is very well rounded and will work with varying hand sizes. The grip gets wider as it comes as you move more towards the front of the gun so that small hands can easily fit in that area and they won’t feel like they’re trying to fit their small hands on a big large surface.
The texturing of the gun is absolutely phenomenal when everything is taken into account. The front strap of the grip has rows of checkering but it gets more aggressive as it moves out towards the sides. It has sharp little squares that stick out and provide just enough traction for your hands without being uncomfortable. The sides of the grips have a deep old school style checkering, that frankly, you don’t notice looks like old school style checkering until you look at it independently from the rest of the grip. The FN logo is embossed in the middle of the grip.
Right above the old school style checkering and the magazine release is the part of the gun that is normally very slick on the FN 509’s competitors where the palm portion behind your thumb sets, there is a nice little stippled style texturing that provides a good place to get traction with the meaty part of your palm. That is probably one of the nicest features on the gun and it lets you know that this gun was designed by shooters and not just engineers.
As far as the overall feel of the grip, it’s absolutely excellent. It feels smaller than most guns, but even people with larger hands are able to get a pretty good grip on the gun. The way the undercut is positioned and with the tang in the grip, most shooters are going to have an easy time getting a high grip on this gun. Ergonomics designs push the shooters to hand high up into the grip, getting, being able to take advantage of all the ergonomics this gun has to offer.
You are not fighting anything on this gun like you would a Glock. Hand a Glock to new shooters who don’t know how to grip a gun and they’re probably going to grip the gun way low. If you hand them this FN, the way the grip is rounded, and just the ergonomics, is going to force their grip higher, meaning they’ll have a better grip on the gun.
The only safety on the FN 509 is the trigger safety itself. The FN 509 trigger is a hinge trigger system, very similar to the Smith and Wesson M&P series. Now personally I will not carry a Smith and Wesson M&P due to the hinge trigger system, and the reason is, my hand often will hit the top portion of the trigger, and it will not allow me to pull the trigger. You need to hit the bottom-hinged portion of the trigger to deactivate the trigger safety and be able to pull the trigger.
The way the FN 509’s trigger is designed, it’s almost impossible not to hit the FN 509 trigger’s hinged portion. Even when I try to just hit the top non-hinged portion of the trigger I can’t do it. I always hit that bottom portion of the FN 509 trigger and reliably release the striker when I pull the trigger all the way.
For good reason, many do not like this hinge style trigger, but I will say FN has executed it as well as a hinge style trigger could be executed.
Now the magazine release on the FN 509 is something that could probably be considered its biggest weakness. The FN 509 was originally designed as a military gun as we’ve gone over earlier in this article. Being a military gun, you could argue that for frontline basic troops that are using a rifle the majority of the time, the chances of somebody having to do a speed reload are really low.
So reliability in the field, meaning the FN 509 magazine release not inadvertently disengaging the magazine thus causing the magazine to not be locked in place when they need it most, could be an issue.
The FN 509 magazine release has built-up areas in the frame around the magazine release, so you don’t have to worry about the magazine being inadvertently disengaged. That said it also makes it almost impossible to fully depress the magazine release without breaking your grip.
I can fully press the magazine release, but I cannot push it far enough to drop the magazine unless I break my grip despite my thumb having ample control and pressure on the magazine release. The built up area is what prevents full pressure from being used when you have a full grip on the gun.
To give you an idea, the magazine release button itself sits halfway down the forward portion of my thumb, between the tip of the thumb and the joint and I still can’t depress it. Most of the time when I depress it my middle finger is actually blocking the magazine from releasing. So I have to break my grip and then press in extra hard and far to get the magazine to drop.
I would consider the magazine release to be the biggest flaw on the FN 509. But if you don’t carry a spare FN 509 magazine that flaw could be considered an asset.
The magazine release button is really well textured and comfortable to use, except for when you get that last little portion you have to press in really hard. Again, I can’t emphasize enough this is probably the only flaw in the design, but realistically how many people are needing to do a speed reload with this gun and it is something you can train around. But the magazine release is a lot harder to use than most other designs.
The upside is its fully ambidextrous and honestly for me the way I grip the gun it seems to be easier to use on the left-hand side than the right-hand side. So part of my issue with the gun could be my grip and the exact size of my hands. This is something you can thoroughly check out in a gun store before purchasing.
Slide Release/Slide Stop
Another ambidextrous feature on this gun is the slide stops. The FN 509 slide stops are placed in a great location, right where your thumb can get easy access to quickly drop the slide once you’ve loaded in a new mag. They are guarded against the bottom by blocking built into the frame so you won’t inadvertently lock the slide back by pressing the slide stop up with your palm when you’re gripping the gun.
While the slide stop/slide releases are engaged, it is much harder to depress the one on the left-hand side than the right-hand side because they are physically aligned to be used for a right-handed shooter due to being built up and having more leverage on that side of the gun.
The slot in the slide that the slide stop/slide release catches a notch on the right side of the slide, so you don’t have as much leverage when trying to drop the slide on the left-hand side.
CALIBER: 9mm Luger
MAGAZINE CAPACITY: 17+1
BARREL: 4 in.
OAL/HEIGHT/WIDTH: 7.4/5.56/1.35 in.
WEIGHT: 26.9 oz.
CONSTRUCTION: Black-Nitride steel slide, Polymer frame
SIGHTS: Steel; 3 Dot
TRIGGER: Striker Fired
MANUFACTURER: FN USA
Overall ergonomics of the FN 509 are absolutely fantastic minus that magazine release issue, the grip itself is one of the few factory grips that I find myself completely happy with. The FN 509 texturing on it could be slightly more aggressive, but again, I can honestly say that’s nitpicking. I am 99% happy with how this grip is set up.
It works well with a variety of hand sizes, from small to large, and the texturing is really good for factory texturing. It could get a little bit slick in extreme, extreme environments, but it’s also comfortable to carry on your skin without issues happening. Besides the CZ P10 series, I haven’t seen better factory grip texturing than the FN 509.
Now that brings us to the slide. The slide has both forward and rear serrations that are slightly angled, and they really allow you to get an awesome grip on the FN 509. The slide on the FN 509 is on the medium to the larger side. It’s smaller than a Sig P320, but it’s larger than something like a Glock 17 or CZ P10c, but the ergonomics as far as manipulating the slide are absolutely amazing.
The serrations are aggressive in that they really allow you to get a great grip on the gun, but they don’t feel that aggressive, but every time you try to grab the gun, it doesn’t take much pressure at all to get a fantastic grip and manipulate the slide. A lot of this comes from the slides of the FN 509 slide having draft angles or tall chamfers that allow your hand to get a good grip on the gun.
This is my favorite factory, non-customization, standard gun serrations.
The sights the FN 509 comes with are just standard metal factory three-dot sights. They do have luminescent paint, and the sight picture is quite good for just basic factory metal sights. The rear notch is a U notch and the front sight is around a 1.25 wide front sight, and the sight picture is really quite good. I can’t emphasize that enough.
Sight cuts on the FN 509 are standard SIG. So you have a variety of options, the FN 509, SIGs, and the Springfield XD series all had the same sight cut. That means that you can mount pretty much whatever you want on this gun. There are offerings from multiple aftermarket manufacturers that we’ll cover later.
Now, the standard FN 509 does not come with a red dot mounting option, but the FN 509 tactical and the FN 509 MRD both have red dot mounting options that are superior to most of the factory red dot mounting plate systems on the market. So those are an absolutely awesome option we’ll link in this article to check out our other reviews.
You can have the FN 509 milled, but you don’t see many people doing custom mill jobs because of the FN 509 tactical and MRD’s mounting system being so great.
So now we get to the trigger. As stated before, the trigger is a hinge style system which understandably a lot of people do not like. But FN has done as good of a job as possible in executing its usability. The Smith and Wesson M & P series, as I’ve stated before, is not safe for me to carry, because I can’t always reliably depress the trigger, the bottom portion of the hinged trigger, deactivating the drop safety.
Now on the FN 509, when you start to pull the trigger, you get to the take-up and then you get to a wall with just the slightest bit of creep. So little creep that can’t feel it and then it breaks in a slightly rolling manner. This trigger feels somewhat plasticky and on the reset, it’s very audible, you just barely feel the reset though. So it’s not a tactile reset.
From the reset, you feel that slight creep and it again breaks with that creepy rolling break.
The trigger doesn’t feel that good when you’re handling it in the gun store or dry fire, but it shoots extremely well. Get this gun out on the range and actually shoot some groups with it and do some stuff under time and I think you’ll be surprised how well this trigger performs.
I’ve never been accused of being a trigger snob, but the FN 509 in a stock format really is an acceptable trigger and falls right where a service trigger should fall.
Personally, the only trigger I might like better in this category would be a stock Glock Gen five trigger.
Cleaning the 509 is fairly easy. There is a takedown lever that you rotate 90 degrees to remove the slide. It’s easy to field strip but if you try to replace parts inside the frame be warned that install can be quite a pain. The FN 509 is an easy gun to field strip but it’s not as easy to replace small parts on.
In my opinion, FN 509 is quite attractive. If you look at some of the features individually, like specifically the texturing, the gun would not seem that attractive, but the way they’ve added them all together they all seem to sum up into a very good looking gun.
If you put the large backstrap on the FN 509, it can look a little bit awkward, but with the regular medium or flat back strap, it really is an attractive gun and the slide serrations and the profile of the slide is absolutely stunning.
Again, I’ve never seen a factory gun that is a standard model with such attractive slide lines.
The ugliest part of this gun is the trigger.
Shooting the FN 509 is an absolute dream. It tracks extremely well under recoil, and the recoil really isn’t that bad. My biggest complaint with the FN 509 is when it comes time to reload because reloading can be quite a pain as far as getting them out of a gun.
But the gun itself is just a track driver and it tracks flat up and down, the recoil is minimal for a gun of this size and the texturing keeps everything in place.