First Impressions: The FN 509

The Army’s XM-17 Modular Handgun System has of course concluded, and the Sig Sauer P-320 has been selected to replace the Beretta M-9 as the Army’s primary handgun, bearing the name “M-17” when it fields. Despite the hotly contested results of the MHS contest (which could be the subject for another article, if not nearly a book), there’s little doubt that the American consumer was probably the one to make out the best in the entire test. As new designs were produced and others modified to attempt to accommodate the MHS, many of these hit the market, including: the M-9A3, M&P 2.0, the Glock Gen 5 (which shared some features of the MHS and FBI Glocks), and a handful of others.

The Gun

Perhaps one of the best handguns to come from the MHS to the commercial market is the FN 509. Let’s take a first impressions look at FN’s evolution from the MHS submission.


The FN 509 is, on its face, a pretty typical modern service handgun. It’s a polymer framed, magazine fed, tilting barrel design that is controlled using an articulated trigger and ambi slide stops and a “full time” ambi magazine release. It’s fed by steel, 17 round magazines and comes with typical 3-dot sights, either white dot or tritium from the factory. FN claims that “over one milion rounds” of testing were conducted when developing the 509, and also has stated that much of the 509’s lineage comes from the FNS-9C. The latter part of that statement is interesting, as one would have thought that the full size FNS would have more in common with the 509, just due to size alone. Speaking of size, the FN 509 is a full sized handgun. Measured in its critical dimensions, the 509 is roughly Glock 17 in height and 19 in length.

Height: 5.56″ (Glock 17 – 5.43″)

Length: 7.4″ (Glock 19 – 7.28″)

Barrel length: 4.0″ 

Width: 1.35″

Weight: 26.9 oz

The 509 comes packaged in a dope, FN branded, soft case that has just enough room for the handgun and two extra magazines. It also includes a total of three backstraps that are held in place by a roll pin. The small is flat in profile – much like a flat 1911 mainspring housing, the medium is arched, and the large is a massive hump complete with extended beavertail.


But the measuring a gun by the numbers and packaging only give us an idea of relative size. As they say, the Devil’s in the details! The 509 seems to be an exceptionally accurate handgun, likely the result of FN’s barrel design. The barrel sports a target crown at the muzzle, which is pretty impressive for a service weapon. A barrel crown prevents the end of the actual rifling from becoming damaged, and enhances long term accuracy. The barrel’s locking interface also seems to stay locked into the slide for quite a bit of rearward travel, which usually results in a more accurate handgun (a la VP9). 


Practical accuracy is also further enhanced by the sight design on the 509, particularly in the notch shape of the rear sight. It’s best described as a “square/U-notch” hybrid that combines the easy reference points of the square cut sights with the quick target acquisition of a wide U-notch.


The orange follower is another one of the “little touches” that makes the 509 well engineered bullet slinger. Don’t mind my hands…

The handgun is also very controllable, both in administrative functions and actual firing conditions. The fore and aft slide serrations are very well cut, and afford a very positive grip when conducting slide manipulations. Additionally, the grip is textured with mix of checkering on the port and starboard sides, molded stippling up high near the thumb rests, and very thick, “chunky” feeling checkering on the front and backstrap.

Initial Performance 

Here’s where things get a little sticky. Although my 509 certainly hasn’t been subjected to any sort of endurance testing by any means, it also didn’t make it through the first 100 rounds without statistically significant issues. Generally speaking, I expect any modern service pistol to be able to function without issue right out of the box, after a minor cleaning. Before some of you get all worked up, I understand break-in, but don’t personally feel that a handgun marketed for self-defense and duty should require it. A stock Glock or M&P will run right out of the box (generally), but the 509 just didn’t quite swing it.

The first 100 rounds were fired very casually. I didn’t have a prescribed course of fire; and I was really just looking to see if the gun would run correctly. After a quick scrub down and lubrication with Slip 2000 EWL, I grabbed 100 rounds of Freedom Munitions 124gr Reman FMJs and began to hammer away. Quick aside – I’ve never had an issue with Freedom Munitions ammo of any kind. Rounds from the same box and lot work just fine in other guns, so I suspect it’s not an ammunition related failure – although no other brands of ammo have yet been tested. 

The Good – 

The 509 is accurate as hell. Like VP9 meets laser guided Copperhead accurate. I suspect that FN’s legendary barrel quality has a lot to do with this, combined with the long locking time of the slide and barrel in battery.

Additionally, the 509 “tracks” well. I don’t know if I could say that it’s the fastest shooting gun I’ve ever fired, but the sights settle back into proper alignment without any concerted effort from the shooter. I believe that this is a product of the aggressive grip along with the heavy spring weight of the 509. Now, recoil spring weight is a double edged sword, but as far as sight acquisition, I find that the relatively heavy spring helps the slide momentum bring the sights back into proper alignment to the shooter’s eye.

If you know how to grip a gun correctly, the 509 isn’t moving in your hand. In fact, the front and backstraps are so coarsely checkered that it became a bit fatiguing on my hand after awhile. But, when it comes to firing conditions, I’d much prefer a gun that hurts the hand but puts rounds on target than one that forces me to continually shift my grip after recoil.

The Bad – 

The 509 didn’t make it through 100 rounds without a few notable malfunctions. First of all, the 509 failed to lock back on an empty magazine at least three times. Although many might suggest that my thumbs may have been riding the slide stop, that’s just not the case – my hands aren’t big enough to do that. I noted which magazine it was that caused the issue, and it seemed to be the same one each time. For whatever reason, it would seem that one of my 509 magazines isn’t lifting it’s follower up high enough to engage the slide stop.

Additionally, I had at four failure to eject (FTE) malfunctions. Two happened during regular (standing, two-handed) fire, and two happened when shooting from a high pectoral retention position. All four times the spent brass failed to clear the ejection port and then was slammed in between the edge of the slide and the barrel hood. Initially I suspected that I was at fault, be it a limp wrist or other bio mechanical issue, but I couldn’t replicate it when I intentionally tried to induce the issue. For now, I’m chalking the issues up to “break in”, although I suspect this has to do with the weight of the recoil spring. I believe the slide is actually closing too fast for the ejector, causing it to slam into battery before the empty case can clear the ejection port.

So, after the first 100 rounds, I’d have to say this:

I have no idea yet how I feel about the gun. 

It seems to be well engineered and have a lot of promise, but the initial issues are a bit concerning to me. I’m not yet ready to trust my life to it by any stretch of the imagination (don’t trust any gun with only 100 rounds through it), and I plan on putting even more rounds through it that I normally would before I make any sort of substantial opinion. The 509 has a lot of promise and it seems to strike some serious sweet spots when it comes to a duty gun or full sized CCW piece, but the initial issues do give me some pause for hesitation.

Here’s to hoping the issues clear up, the gun breaks in, and Safariland releases a light bearing holster for the 509!

Until Victory.