The U.S. Army’s search for a standard-duty pistol to replace the Beretta M9 ended in January 2017. SIG SAUER won the military contract. Civilian shooters also won because the competition among the various pistol manufacturers resulted in an all-new group of top-performing high-capacity, polymer-frame pistols.
FN America’s entry in the military trials (known as the Modular Handgun System program, a.k.a. MHS) is the FN 509, and it’s the result of years of rigorous research, development, and testing. The FN 509 may look to the casual observer to be just another highly refined, polymer-frame, high-capacity, striker-fired 9mm pistol, but there’s more to it than meets the eye.
Featuring a full-size, all-four-fingers-fit polymer frame, the FN 509 is serialized on the bottom of the dustcover via a steel plate mortised into the accessory rail rather than on a steel skeleton contained inside a removable polymer frame shell. As such, the frame size is permanent and can’t be converted into a compact version.
As for the slide, it’s machined from stainless-steel bar stock, features modern contours and sights, and houses a 4.0-inch barrel that cams up into the massive ejection port to lock into battery. Barrel and slide are finished in matte black via a ferritic nitrocarburation process similar to nitride. As mentioned before, it’s of striker-fire design, and the magazine capacity is 17 rounds.
However, these facts don’t begin to do justice to the FN 509. Design features are deeply researched and finessed to performance-enhancing perfection. The stainless slide features tapered sides for easy holstering, a lowered and flared ejection port for reliable ejection of empties and unfired cartridges, and drift-adjustable sights front and rear. Luminescent three-dot paint offers low-light performance. (Tritium night sights are available for law enforcement.) Made of steel, both sights are robust enough to pound spikes. The rear sight offers a vertical front face useful for racking the slide one-handed on a belt, steering wheel, concrete curb, or whatnot.
The forward end of the external extractor is engineered to protrude slightly when a round is chambered. It provides a visual and tactile loaded-chamber indicator.
FN is renowned for its cold-hammer-forged barrels, and the FN 509’s tube is manufactured in-house. Made of stainless steel, it features a polished feedramp and chamber and a recessed target-type crown. Not only should FN 509 barrels prove to be accurate, but also they should offer superb barrel life, corrosion resistance, and durability.
Uniquely, the FN 509 is fully ambidextrous, so you don’t need to remove and swap controls from one side to the other. There’s a magazine release button and a slide lock lever on each side. The grip is well contoured for a high, recoil-controlling grasp and features three distinct textures: a “dragon scale” raised-square pattern on the frontstrap and backstrap, coarse checkering on the side panels, and a stippled-type pattern on each side of the upper panel just above and aft of the mag release.
Each FN 509 pistol ships with two different backstraps. The factory-installed backstrap is curved; the spare is a slender straight-backed version. This enables the user to tweak grip diameter and feel to suit his or her hand. Tools are required for the swap. Drive out the tiny retaining pin, exchange the backstraps, and replace the pin.
A low “fence” protects the slide lock from accidental activation, and the trigger guard is engineered large enough for comfortable use with gloves. My two favorite frame features are at the bottom of the grip. First, there’s a lanyard loop. Originally added to military revolvers in cavalry days to prevent the loss of an empty sidearm if a mounted trooper had to drop it and draw his saber, it’s a feature that has somehow hung on and is still included in many military sidearm specifications. Each MHS contender I’ve examined included a lanyard loop. As a horseman from way back, I find the lanyard loop lends a little nostalgic charm to an otherwise thoroughly modern pistol.
Second, the grips are scalloped on each side just where they meet the magazine’s floorplate, allowing for a good grip in case the magazine needs to be manually torn out of the gun to clear a stubborn malfunction. On a related note, the forward edge of the magazine’s floorplate has a sturdy lip extending just enough that it could be hooked on something and the magazine pried out one-handed should the need arise.
As for the magazine, it’s steel with a fully welded seam. Perforations enable the shooter to instantly see how much ammunition remains. The high-visibility orange follower is constructed of a low-friction material. Two 17-round magazines are included with each pistol, and 10-round versions are available for states with capacity restrictions.
The FN 509’s trigger features the hinged trigger-shoe safety popular today, and it has a nicely rounded contour that feels good under the trigger finger. Basically of two-stage design, there’s significant take-up, then a crisp wall against which the shooter may stage and squeeze through when a precise shot is required.
In addition to the hinged trigger-shoe safety, the FN 509 features an internal safety that blocks the firing pin unless the trigger is squeezed rearward. No version with an external manual safety is offered, at least not initially.
Field stripping is fast and easy. Drop the magazine, clear the chamber, lock the slide rearward, and rotate the takedown lever on the left side of the pistol 45 degrees until it points downward. Release the slide, squeeze the trigger, and draw the slide assembly forward off the frame. Lift the captured recoil spring assembly and barrel out of the slide and you’re done.
To reassemble, replace the barrel and recoil spring, align the slide on its rails, slide it rearward and engage the slide lock. Rotate the takedown lever to its horizontal position.
During the 2017 SHOT Show I attended a prelaunch introductory event for the FN 509 and put several hundred rounds through one. Distance was limited and light was poor in the indoor range, but my initial impression was that the FN 509 possessed unusually good ergonomics, and that impression strengthened the more I shot it.
Several months later, after receiving another FN 509, I ran a collection of my favorite 9mm ammo through it at my home shooting range. In all, I put close to 200 rounds through it during an extensive shooting session. I found the pistol to be 100 percent reliable. It balances well and points naturally.
As part of the MHS requirements, competing models were required to meet some impressive accuracy and reliability criteria. Pistols were expected to offer a 35,000-round service life, which, for obvious reasons, I couldn’t test. On the other hand, each competing model was challenged to keep nine of 10 shots inside a 4-inch circle at 50 yards—that I could test.
After completing my standard 25-yard accuracy tests by firing three consecutive five-shot groups for average with each type of ammunition, I chose the most consistent—which was the Federal 147-grain HST—moved my target to the 50-yard line, and fired a 10-shot group. I managed to keep six of the 10 in a 4-inch group. At that point, it became clear that my middle-age eyesight was providing a bit of a roadblock and no doubt the FN 509 would have performed better from a Ransom Rest.
As the accompanying chart indicates, the FN 509 averaged less than 3 inches at 25 yards with four of the seven factory loads I tested. That’s not bad—certainly within acceptable fighting-pistol parameters—but it’s not match-winning accuracy, either. Candidly, I struggled with the trigger.
As I mentioned earlier, the trigger is essentially a two-stage type. And on my pistol, the trigger’s first stage gave me fits. Rather than a light, smooth swing through to the second stage, it is heavy and—for lack of a better word—rubbery. The trigger’s reset isn’t as short as some, but it is nice and distinct. Factory specs rate FN 509 triggers at between 5.5 and 7.5 pounds from the factory; measured on my Lyman digital trigger gauge, my pistol averaged 6 pounds, 11 ounces over a series of five measurements, with 7 ounces of variation.
The trigger’s rubbery feel made it difficult for me to achieve a perfectly clean release while shooting for accuracy. It’s a shame. Judging by the occasional outstanding group I did produce, I think the FN 509 has inherent accuracy, but it’s just difficult to tap into without a really crisp trigger. Perhaps several hundred rounds worth of break-in would clean up the trigger’s feel, and maybe, just maybe, evetually some company will offer a replacement trigger for the FN 509.
With my formal testing complete, I put up a couple steel torso plates and ran a series of informal drills to more thoroughly evaluate the FN 509’s handling characteristics. Failure drills, Bill Drills, and casual shooting at “threatening” dirt clods revealed the pistol’s virtues. It points naturally, balances well, and recoils politely. Reliability throughout my entire shooting session was stellar, just as you’d anticipate in a pistol built by the company that supplies the bulk of our armed forces’ machineguns.
I haven’t fired all the pistols submitted for the MHS program, but I’ve shot many of them, and each has been outstanding. While the FN 509 did not win the coveted military contract, it is a fine service pistol, and it stands among an elite group of the best-designed polymer-frame, high-capacity pistols available. Like a trusty workhorse, it will provide dependable service at the range, on duty, and in defense of the home.