7 Best FN 509 Upgrades

The FN 509 has wide range of aftermarket upgrade support. Whether you are fine tuning your existing gun or build one from scratch. Here are 7 best FN 509 upgrades you should consider to enhance its tactical capabilities, ergonomics and reliability :

FN 509 Upgrades

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Optic Ready Slide

fn 509 slide upgrades

There are FN 509 factory slides available for anyone who is interested in swapping between slides without swapping red dot sights, caliber conversion or barrel configurations.

Original FN 509 owners can also convert their guns to the FN 509 Tactical or FN 509 LS Edge if the correct slides are purchased.

The FN 509 owner can stick with the factory grip frame and use different slides for different applications. 


fn 509 compensator

FN 509 with a threaded barrel can attach a 9mm compensator to reduce the muzzle flip. Even though the muzzle flip reduction isn't dramatically significant, but it's a performance boost when shooting heavier grain 9mm or plus P ammo.

The compensator will go on any FN 509 threaded barrel with 0.5” x 28 thread pitch.

Apex Action Enhancement Trigger

apex fn 509 trigger

The Apex Action Enhancement Kit for FN 509 pistols is a straightforward drop-in replacement for the factory components.

The trigger upgrade innovative, patent-pending design substantially reduces the trigger pull weight, bringing it into the desirable 5.5 lbs range. The trigger upgrade also reduces trigger travel, pre-travel, over-travel, overall trigger travel, and trigger reset distance.

Overall it's a trigger with a smoother uptake and a crisp, cleaner break than the FN factory trigger.

Streamlight TLR 1 HL

streamlight tlr 1 hl fde

For a home defense FN 509, a light is a must. Above all the options available, the Streamlight TLR 1 HL is the best. It's easy to mount on any M1913 pic rail with adjustable tension screw mount. The 1000 lumen and 15000 candela intensity output is plenty for close quarter low light target  identification.

The flood and hot spot pattern is well balanced to see straight ahead as well as the surrounding from 9 o clock position to 3 o clock position. In addition, the paddle switch is extremely easy to operate without hard press.

Some even suggest that its 4.18 oz weight added can help reduce muzzle flip.

Firing Pin Striker 

fn 509 apex firing pin

The Apex Tactical FN 509 stainless steel firing pin is heat treated for enhanced durability than the factory firing pin. This is a direct drop-in replacement to improve the trigger plug and reliable primer hits with various 9mm ammo. FN 509 owners can use this as a backup if the original firing pin wears out.

According to Apex Tactical, dry firing is okay with a snap cap.


FN 509 holster

For those seeking an optimal concealed carry Inside the Waist Band holster for their FN 509 with Streamlight TLR-7/7A Light or a full size Surefire X300U, look no further than the "We the People Holster." 

The holster is crafted from durable Kydex, this holster combines comfort and discretion seamlessly. Its slim profile ensures effective concealment under various clothing types.

The Holster include adjustable retention for personalized comfort, versatile ride and cant adjustments for diverse carry options

  • Adjustable clip offering up to eight different positions
  • Protective sweat guard to minimize contact between your gun and body
  • Secured belt clip for smooth draws
  • Compatibility with standard pistol red dots.

Red Dot Sight

trijicon sro

The Trijicon SRO or the Holosun 507C offer fast target acquisition for FN 509 shooters, and never miss the dot after each shot. Both red dot sights fit the RMR footprint.

The Trijicon SRO's circular window is slightly larger than any normal size red dot where the extra window width stretching from the top and sides allow the shooter to self correct dot misalignment with much more margin of error before it disappear within the window.

As far as having a durable carry optic with a large window, the Holosun 507C is recommended. It has long battery life, and it features side loading battery tray, so the user doesn't have to remove the sight for battery swap.

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