Gun Review: FN 509 Midsize Tactical 9mm Pistol

The FN 509 Midsize Tactical is the Goldilocks of the FN 509 line, fitting comfortably between the compact and full-size tactical models. Just like both of those previously released pistols, FN has given the market another great-shooting, feature-filled handgun with lots of options, right out of the box.

One of the nice little things FN has been doing for some time now is the box itself. The 509 Midsize Tactical comes in a quality soft carrying case with slots for multiple magazines and all of the assorted hardware that comes with the gun.

And that’s hardware a-plenty.

Each pistol comes with two magazines, a 15-round flush fit version and an extended 24-round magazine. They both work exactly as they should, locking firmly in place and smoothly ejecting the empties. I have never had any problems with either of them.

You’ll also find two backstraps for each gun, both equally textured but one simply flatter than the other. The pistol comes with the larger/more rounded backstrap installed.  A lanyard hole is drilled into the bottom of each backstrap.

FN’s got the best factory-direct optic mounting system of any of the major manufacturers.  Inside that same case you’ll find the optic mounting kit, compatible with a wide arrange of pistol-purposed optics. That kit includes all of the plates and screws you’ll need, along with an extra O-ring and wrench.

Installing a Leupold Delta Point Pro was no problem at all, and I was especially glad to see an insert included for this optic that allows it to sit flush with the rear of the cut-out. It’s so nice not to have to go online and search for the one bracket, screw set, insert, whatever tiny part you need just to get your optic on your gun. FN includes it all, right in the bag.

Beyond the easy optic installation, you’ve also got great factory irons. FN includes suppressor-height tritium 3-dot night sights on all their Tactical models that co-witness with your optic.

The rear sight is protected by sharply angled “wings” on either side. Those wings are serrated on the front so you can rack the slide or help clear a malfunction just by hooking them on an object and pushing hard. Since the wings protect the rear sight, there’s no real danger of moving the sight itself in the process.

With the exception of the size, the slide and frame is the same as the other pistols in the FN 509 Tactical series. You’ll find the same PVD finish, same multiple and aggressive textures throughout, same pic rail, the same slide serrations. The Midsize Tactical has the same ambidextrous slide stop/release. And the same half-moon cut at the bottom of the grip to help you rip the magazine out in the event of a stoppage.

The oblong magazine release is heavily textured and reversible. With the undercut on the trigger guard, I found I needed to move my middle finger out of the way to depress the magazine release. Shooters with size Large hands are pretty used to this by now.

The trigger on the entire 509 series is okay, but just. Yes, it’s better than a Gen3 GLOCK, but that’s about as far as I’ll go. There’s some grittiness to it, no matter how many times it’s been fired or how clean you’ve got the gun.

The trigger break measured at 6 lbs, 0.2 oz over five pulls from my Lyman digital trigger scale. There is a total of 1.8oz of difference in those pulls, not bad for a mass-produced striker-fired pistol.

With it’s 5.8″ sight radius and the usual high quality FN cold hammer-forged barrel, precision is very good, especially for a pistol of its size and weight. The best shooting round I found for this gun was the same as for the FN 509 LS Edge Longslide, the Winchester 124gr +P PDX1 JHP.

The Midsize model didn’t quite live up to the precision of the Longslide version, printing 2.2″ five round average groups over four shot strings off bags at 25 yards. That said, nothing I shot scored over 2.8″ groups on average, and that was Winchester’s 115gr FMJ round.

When multiple weights and types of ammunition group the same, that’s usually my hint that it’s the shooter’s eyes and ability as much as the gun itself. All groups were fired with the factory iron sights.

The FN 509 Midsize Tactical shot just as reliably as all of the other 509s TTAG has reviewed. I put 500 rounds through the gun for this review, with a mix of 115gr FMJs, 124gr +P JHPs, and 147gr FMJ’s from a few different manufacturers. Three hundred of those rounds were fired with an ancient Advanced Armament Company silencer attached.

With or without the can, I never had any issues with the gun in any way. It ran and ran. After initially spraying it down with CLP, I never lubed or cleaned the gun in any way during the review. I did have to tighten the silencer back down a few times.

The FN 509 Midsize tactical is simply the model that fills in the gap in size already offered by FN. I really liked the FN 509 LS Edge, but the Midsize Tactical is the more useful gun.  The extreme amount of options FN provides with this gun makes it better than average at just about everything.

The Midsize Tactical is big enough for size Large hands to get a full grip on the gun with a flush fit magazine, and it’s small enough and light enough to carry every day. You can run it light and slick, or throw a red dot on it right from the factory.

Those of you so inclined can swap the 15-round magazine for the 24 count, screw on the suppressor of your choice, and operate very operationally. It’s also a whole lot of fun to turn to the NV setting of the Delta Point Pro, goggle up, and see how close you can get to a wild pig to put a few 147gr FMJs in it’s noggin. Ask me how I know.

Specifications: FN 509 Midsize Tactical

CALIBER: 9mm
OPERATION: Double-action
MAG CAPACITY: 10 or 15/24 Rd.
WEIGHT: 27.9 oz.
BARREL LENGTH: 4.5″
OVERALL LENGTH: 7.9″
TWIST RATE: 1:10″ RH
HEIGHT: 5.2″
WIDTH: 1.35″
MSRP: $1,069 (about $900 retail)

Ratings (out of five stars):

Style and Appearance: * * *
The PVD coating is even and well done throughout. Somehow FN got the color of the metal slide and polymer frame very similar. Whoever was able to accomplish this witchcraft at FN needs to call whoever’s in charge of the SCAR.

Customization * * * * *
Best in class, and best in the 509 Series.

Accuracy * * * *
Just a tiny bit better than average.

Reliability * * * * *
Perfect, with any round, suppressed or not.

Overall * * * *
The mediocre trigger is the only thing keeping the FN 509 series from dominating this market. The 509 — and specifically the Midsize 509 Tactical — represent what shooters have come to demand, and what’s possible to deliver, in a modern handgun.