FN Herstal was established in Belgium in 1889 as a manufacturer of military arms, and over the course of the last 128 years, the company has produced a wide variety of weapons ranging from the Browning Hi Power and Mauser-style bolt actions to the more modern SCAR, P90 and M240 firearms used by militaries all around the globe. The brand is still the largest small arms exporter in Europe, and its U.S. division, FN America, based in South Carolina, produces a number of firearms for both military and law enforcement professionals as well as civilian shooters.
With such a lengthy record of firearms engineering and manufacturing, FN was an obvious choice to provide a test pistol for the U.S. military when it was looking for a contract handgun. The firearm FN submitted to the test was the 509, a striker-fired, polymer-framed 9mm with a 17-round capacity. Although it wasn’t chosen for military adoption, the 509 is now available to U.S. shooters.
Unlike many guns that start out as full-size models and are then scaled down to serve as carry guns, the FN 509 borrows its architecture from the brand’s existing FNS Compact. The 509 is not simply a larger version of the FNS Compact, though. Changes were made both internally and externally to meet military testing guidelines, so although the 509 is derived from the smaller gun, it is a unique firearm.
Many of the 509’s features are similar to those you’ll find in the sea of full-size striker-fired polymer guns on the market. The large slab-size grip has interchangeable backstraps for added comfort and convenience. The external controls—slide stop, takedown lever and magazine release—are contoured to fit close to the frame so they won’t hang up when the gun is drawn.
Both the mag release and the slide stop are truly ambidextrous—as opposed to reversible. The gun feeds from a double-stack metal magazine, the trigger breaks at 6.5 pounds, and there’s an accessory rail on the front for adding a laser or light.
That’s how the FN 509 is like other striker-fired guns, but there are subtle nuances that make it stand out from the rest. The engineers at FN have plenty of experience building combat weapons, and they incorporated many user-friendly features into this pistol that separate it from competing guns.
It starts with the sights. The durable, metal fixed front and rear sights are dovetailed into a short rib that runs the top of the length of the slide, and the forward edge of the rear sight is flattened, so it’s possible to rack this pistol while using one hand.
The sights are slightly taller than the average irons on a polymer gun, too, rising about a quarter of an inch above the slide. The sights have a three-dot configuration and feature luminescent paint on the civilian model (night sights on law-enforcement models). The rear sight has a cutout so the dots are recessed, which reduces glare—a small but functional touch.
FN gave the 509’s slab-sided grips three distinct texturing patterns on various surfaces. The frontstrap and backstrap have textured horizontal lines. The sides have traditional checkering that keeps the pistol firmly in hand without being too aggressive. The slightly recessed thumb and trigger finger grooves near the top of the grip have comfortable texturing that provides good contact with the gun.
The grip itself is 1.4 inches wide, and there are two interchangeable backstraps: one that offers a rather straight profile and one that offers more of a “hump” that fits more deeply in the pocket of the hand. It’s 2.75 inches from the bottom of the trigger guard to the bottom of the magazine, so there is plenty of space for even the largest mitts, and the grip angle promotes a high hold for better control of the gun when firing.
The trigger guard is undercut at the rear for added comfort, and the oversize trigger guard accommodates gloved fingers without any issues. The two-piece trigger was great, providing a consistent pull and a short reset. This is a gun that can shoot as quickly as you can get the front sight back on target. The face of the trigger is wider than that of many other guns and smooth, and it offers plenty of space for your finger and excellent control.
Other key features include a beefy steel slide with various angles machined into the metal. There are wide, functional slide serrations fore and aft. The black matte non-glare nitrocarburized finish is durable—it stood up to the testing as well as the various bumps and dings that the gun was exposed to during the lengthy photo shoot.
The four-inch cold-hammer-forged stainless steel barrel has a recessed crown to protect the rifling. There’s a large external extractor on the slide that doubles as a loaded-chamber indicator, albeit a relatively small one. A red dash is visible when a round is in the chamber, and it is possible to get a tactile verification that the chamber is loaded. This is especially so for left-handed shooters who can simply ride the thumb of the shooting hand up the slide.
The oval magazine release button is large and functional and sits under a narrow polymer lip in the frame, an extra measure of protection against an accidental magazine drop. There’s a similar polymer lip surrounding the slide stop that proved to be quite functional. More on this later.
One of the unwritten rules of new polymer guns is they need to be easy to disassemble for basic cleaning and maintenance. Breakdown of the 509 is simple and straightforward. Simply drop the magazine on an unloaded firearm, lock back the slide, rotate the breakdown lever 90 degrees, release the slide forward, pull the trigger and the slide rides forward on the rails and into the hand.
One look at the internals of this gun makes it clear FN built this pistol to function dependably and last for thousands of rounds. The internal chassis rails are smooth and robust, and the barrel’s feed ramp is neatly polished and smooth. A 17-round magazine comes with a low-friction orange follower that makes it easy to see when the mag is empty, and FN provides two mags.
Because there are so many options in the polymer 9mm market, it’s instructive to examine how the 509 stacks up against some of the competition (see chart). In most regards, all the guns listed—the 509 as well as the Glock 19 Gen 4, Springfield XD, Ruger SR9, and SIG Sauer P320—are similar in size. The 509 has the widest grip, but not by much, about a tenth of an inch. That won’t make much difference when you’re carrying the gun, but it does offer more surface area to control recoil and muzzle rise.
The FN 509 is at the top of the capacity leaderboard, tied with the Ruger, at 17. It is slightly taller than the other guns listed, and barrel length and overall length are close across the board. At 27 ounces, the FN is also in the middle of the pack in terms of weight. It carries a suggested retail price above the Ruger and Springfield guns, is on par with the Glock 19 and is slightly below the SIG P320 Nitron Carry.
Unless you’re stuck on having the lightest, shortest, thinnest or highest-capacity gun, all of these pistols play in the same arena. If you’re looking for the least expensive polymer 9 on the market, that’s not the 509. What really matters, I believe, is how a gun feels in the hand and how it shoots.
As you can see in the accompanying chart, in terms of 25-yard accuracy off a fixed rest, the 509 shot well with most every load tested. The Hornady Steel Match load with the 125-grain HAP (Hornady Action Pistol) bullet and the SIG Performance Elite V-Crown 124-grain load shot particularly well, and the overall level of consistency is a byproduct of quality engineering and attention to detail during the manufacturing process.
Accuracy was enhanced by having clear sights, a grip design that allows for a solid hold on the gun and a trigger that is quite good. While the FN’s trigger pull is on par with other guns in this class that I’ve fired, I was especially a fan of the FN’s rounded, smooth surface and the short, crisp reset.
There was one issue with reliability. While four of the five loads ran through the entire test without a hitch, one load—Hornady’s 147-grain XTP—wouldn’t feed reliably. In every case the issue was the same: The slide wouldn’t close completely when a fresh XTP load was chambered. Getting back in battery required a strong push on the rear of the slide, and the problem continued throughout the test. One round would feed, the next wouldn’t.
If you only fired this round in the 509, you’d swear that either the load or the gun had a flaw, but I shot about 200 rounds of other ammo through the gun without a hiccup, including Hornady Steel Match. Likewise, I’ve used Hornady XTP loads in a variety of other polymer 9mms over the years, and I’ve never encountered the issue before. It just seems to be a chemistry issue between that load and this particular gun.
I did manage to fire three five-shot groups with the XTP loads, and accuracy wasn’t an issue despite the feeding glitches; the XTP loads averaged about 1.5 inches.
While I was impressed with the 509’s accuracy off the bench, it really shines when you’re on your feet engaging targets offhand. As with most guns, I went through a list of fairly standard drills with the 509: double-taps, failure drills, tactical reloads and a series of other movement drills.
The 509 performed well in all of them. The grip design, balance and highly visible sights help you deliver follow-up shots in a hurry, and the gun manages recoil well and feels good in the hand.
Initially, I was a little disappointed that the slide stop on this gun was so small. That usually spells trouble for fast reloads, but the small polymer lip in front of the slide stop I mentioned earlier acts as a reference point to allow for instant slide drops when reloading and moving—even when wearing shooting gloves.
With so many polymer 9mms on the market, it’s tough to say that one really stands out from the rest, but the engineers at FN got this one right. Of course, the gun you choose to carry is largely a matter of personal taste and which grip, sight or control layout appeals to you, but I can say with confidence that the 509 deserves a place on the short list of best polymer striker guns on the market today.
A seasoned shooter once told me the best guns are part hammer and part scalpel: a durable tool and a precision instrument combined in one package. That’s a good summation of the new 509. It floats near the top of the pool of competing guns and has several features that make it stand out. FN says the 509 endured more than a million rounds of ammo during testing, and the final product leads credence to that claim.