FN America’s polymer fn 509 compact is a mid-sized 9 mm double-action semi-automatic pistol that comes with a pair of either 10 or 17-round low friction polymer magazines. Important dimensions include a 4.0” long barrel with a 1 to 10” RH twist, 1.35” width, 5.56” height and an overall length of 7.4”. Because it’s a polymer frame, the weight is a pleasant 26.9 ounces. The gun comes in one color: black.

The fn 509 compact was developed in response to the US Army and US Air Force’s 2015 XM17 Modular Handgun System competition and was thus expediently evolved from FN FNS compact semi-automatic for this purpose.

The fn 509 compact comes standard with fixed 3-dot combat-style luminescent sights. The sight radius between the two is 5.79”. Note: the FN 509 Law Enforcement only version is available with fixed 3-dot green tritium night sights.

The slide has aggressive diagonal slide grip serrations at front and back and a loaded chamber indicator.

The 4.0” long barrel is cold hammer-forged from stainless steel. It’s fronted by a recessed target crown. Both the feed ramp and chamber have been polished for increased reliability.

Replaceable steel slide rails sited in the polymer frame are a particularly compelling feature of the fn 509 compact.

Moving down, the fn 509 compact slide stop lever is on the left favoring right-handed shooters. However, the pistol has ambidextrous manual thumb safeties and an extended magazine release that’s paired with a nice concave groove behind it for profile reduction and increased comfort. A non-manual safety model is also available.

The under-muzzle MIL-STD-1913 accessory rail has four slots for attachments.

The gun is double-action and has a striker-fired autoloader. The gently curved trigger has a trigger pull rated at 5.5 to 7.5 pounds and sits in a curved trigger guard.

The pistol grip features integrated flattened pyramid side grips that are enhanced by the elegant FN herald logo and texturizing further toward the top. The gun comes with two interchangeable backstraps: one is curved and one is flat. Both have flattened rectangular top pyramid grips. The front’s integrated grips are similar.

FN America is the American subsidiary of FN Herstal of Belgium, which has made arms since 1889. The fn 509 compact is manufactured at FN America’s Charleston, South Carolina facility and is thus Made in USA.