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FN 509 Review: Reliability meets Precision

Taking a look at the mid-size striker fired pistol market these days can be a bit daunting. It seems that every company under the sun has an offering that is competing for your attention. So, with all this going on why should you look to FN, a company who has not always had the largest impact on the civilian market. There are of course some notable exceptions like the high power, released in 1935 and the FNX 45 which was released in 2009. Of course they have released other products through the years, these are just a few highlights. If you were to ask most people what they think about when you mention FN though, they would likely say the FAL, M249 or the M240. 

With that being said the FN 509 MRD midsize is a very solid entry into this competitive field and a gun that you should definitely take a look at if you’re in the market.  


The FN 509 MRD midsize comes with all the features one would expect for a pistol of this type. A few of these are listed below: 

  • Fully ambidextrous controls
  • FN Low Profile Optics Mounting System with plate adapters for direct mounting of more than 10 optics
  • Enhanced grip textures which enables faster follow-up shots in all conditions
  • Improved flatter face trigger
  • Flush fits 15 rd magazines, will also accept 17 and 24 rd magazines
  • Iron sights pre-installed that co-witness with most optics. 
FN 509 magazines and pistol

From the factory the pistol ships with all of the standard accessories you would expect, like a lock, extra back strap and magazines (15 rounds each). In addition to this you get the mounting plates I mentioned above which let you put just about any optic that you could want on the pistol. As we’ll cover in more detail later on the FN 509 MRD midsize has many of the same features as other pistols, but it executes them all very well in a pistol that can serve multiple roles. 


The FN 509 MRD midsize fits into an odd middle ground when it comes to pistols. It’s size/weight, coming in at 26.5 oz, 7.4 in long, 5.2 in tall and 1.35 in wide puts it on the large side for a concealed carry gun and on the small side for a duty/home defense gun. By way of comparison a Glock 19 comes in at 23.81 oz, 7.28 in long, 5.04 in tall, and 1.34 in wide.  This article is by no means a comparison between these two guns, the Glock 19 is just a gun that most people are familiar with for reference. 

The barrel length on the FN 509 MRD midsize is 4 inches; which like I mentioned with the other stats is about a long as you would want for concealed carry, but still shorter than most full size pistols.  

FN 509 breakdown with all pieces ready to clean


(how it feels, shoots, cost and my experience with it):  

Alright, lets get into the meat and potatoes of this thing. How does the gun perform? A short answer to that question would be very well, but let’s get into a bit more detail than that. 

Man holding the FN 509 pistol aiming

Grip & Texture

The first thing that you’re going to notice when you pick up this handgun is the texturing on the grip. FN uses different textures on different parts of the grip giving good purchase on the handgun regardless of shooting conditions. While at the same time having it not feel like the thing is wrapped in sand paper. One thing I particularly enjoy is the unique grip texture where your thumb and trigger finger should lay, which lets you feel if your grip is off or not. The slide also has aggressive serrations on both the front and back, this isn’t really something I notice much while shooting but it’s important to some people. 

FN 509 magazine release and texture on the grip

The magazine release is larger than on most other pistols and nicely checkered. Given it’s size I was initially worried that I might inadvertently drop my mags while concealed carrying (appendix mostly) but so far this hasn’t happened. 


When shooting a gun the first thing I normally notice is the trigger. The FN 509 MRD midsize comes with a good trigger right out of the box. I wouldn’t call the factory trigger great, but it is good and there are aftermarket options if you want to go that route. Like most striker fired pistols the 509 uses a safety mechanism integrated with the trigger, this one is fairly similar to the M&P series of pistols in that the whole lower portion of the trigger is hinged. Once you start pulling the trigger there is an initial slack take up and then a wall. There is some travel past the wall, the pull weight feels like it is consistent with the manufacture’s advertised 5.5-7.5 lbs, followed by a short reset. 

FN 509 trigger close up view

Iron Sights

Another thing that you’ll notice right off the bat is the co-witnessed iron sights, not every optics ready pistol out there comes with sights that are high enough to co-witness, which at this point blows my mind. Like everything else in life everyone has an opinion on what makes a good set of sights. For my two cents I like my backup sights totally blacked out, when my red dot is working I don’t want anything else to draw the attention of my eye. I tend to run weapon lights on my handguns a lot of the time so if I need to use the backup sights at night it doesn’t really matter that they don’t have tritium in them. 

FN 509 Cowitness iron sights with red dot sight

Concealed Carry & Duty Carry

I’ve used this pistol for concealed carry, duty use and competition in the past three years. Because of the features we’ve already discussed it has performed well in every category. The midsize comes in at a point where it can flex into multiple roles and is a good option if you can only purchase one handgun. While concealed carrying the 509 MRD midsize there have been times, where I felt it was a bit large. These instances happened mostly in the summer months and largely depended on my clothing choices. Most of the time though this pistol concealed well and with a red dot allowed me to routinely hit silhouette targets at 50 yards. Plus, the flush fitting 15 round have a good amount of capacity. 

FN 509 with a concealed carry holster

In duty use the 509 MRD midsize has also proven itself to be very capable. Thanks to Los Angeles PD adopting the 509 as their duty pistol Safariland makes a variety of duty holsters for the platform. If you’re flexing the midsize up to fulfill a full size pistol’s job all you’ll need is a weapon light of your choice and some larger magazines. The 17 and 24 round 509 magazines both fit the midsize model, there are also spacers available so the contour of the grip continues down the magazine.

I carried this pistol as a duty gun for about a year in this configuration and had no trouble keeping up with people packing full sized models. The recoil impulse is tame and allows for fast follow up shots, plus the 4 in barrel provides enough velocity to get good terminal ballistics. 

FN 509 with extended magazine, flashlight, and red dot sight


When it comes to competition use I’m not running this pistol in some high speed USPSA competition and it wouldn’t be suited to that. But I do use it regularly in two gun competitions with the larger capacity magazines and have had good results. It would also do well in a IDPA style competition. Essentially any competition with a lean towards realistic shooting conditions is where this pistol is going to shine. If you’re looking for the cutting edge of speed you’re going to want a purpose built gun. 


An online search for current pricing has these pistols going for about $730 from various retailers. Even though this is slightly more than some of the 509’s competitors I still believe that this pistol is worth that price and it’s performance will not let you down. 

FN 509 with flashlight and red dot sight sideview of pistol



  • Able to be used in a wide variety of situations/use cases 
  • Comes with adapter plates for just about every optic out there
  • Flawless reliability in the thousands of rounds I have through mine. Including a lot of cheap steel cased ammo. 
Man holding FN 509 pistol


  • While this pistol can be flexed into many roles it may come with trades offs (like size) over a pistol built for a specific use case. 
  • FN’s products tend to run slightly more expensive than the competition. 


It is certainly true that there are other pistols in the same size category as the FN 509 MRD midsize which cost slightly less. It is also true that a pistol built for a specific use case like concealment, duty or competition will be better at those specific things. But, if you are looking for a very reliable, reasonably priced handgun which will fill a wide variety of roles the FN 509 MRD midsize is definitely worth your time. 

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