The FNP-40 is the predecessor to the modern FNX line. Introduced in the mid-2000s, it was FN’s first major success in combining a polymer frame with a traditional hammer-fired DA/SA (Double Action/Single Action) system. It was designed primarily for law enforcement and military use, aiming to provide the weight savings of a Glock with the familiar trigger mechanics of a SIG Sauer or Beretta.
Replaceable Chassis Rails: One of the most innovative features of the FNP series was its fully replaceable frame rails. Most polymer guns have rails molded into the frame; if they wear out, the gun is totaled. On the FNP, the rails could be swapped out, theoretically extending the life of the pistol indefinitely.
Omega-Style Versatility: It features a frame-mounted decocking lever that allows you to safely lower the hammer on a live round. Most FNP-40 models are decocker-only (DA/SA), though a "USG" (Ultra-Safe Gun) variant was produced that included a manual safety for "Cocked & Locked" carry.
Cold Hammer-Forged Barrel: Even back then, FN was using its world-class stainless steel barrels with a 1-in-16" twist, giving the FNP-40 exceptional accuracy for a .40 S&W duty pistol.
Fully Ambidextrous Decocker: The decocking levers are present on both sides of the frame, a feature that was quite advanced for its time.
Checkered Texture: The grip features a "pebble" texture on the sides and horizontal serrations on the front and back straps. While not as aggressive as the modern 509, it provides a solid, comfortable grip.
The FNP-40 was eventually phased out in favor of the FNX-40 around 2010/2011. Here are the key differences if you are looking at them on the used market:
Magazines: Crucial Note: FNP-40 magazines are not compatible with the FNX-40 (and vice versa). The floorplates and locking notches are different.
Safety/Decocker: The FNX combined the safety and decocker into a single lever; on the FNP, they were usually separate functions or models.
Backstraps: The FNP usually came with two backstraps (flat and arched), while the later FNX/509 series expanded this to more modular options.
Bore Axis: The FNX has a slightly lower bore axis and a deeper grip tang for better recoil management.
The FNP-40 is discontinued and has been for over a decade. While they are still very reliable shooters, they have become somewhat of a "legacy" platform.
Parts Availability: Basic wear items (springs, pins) are still available through specialty shops like Midwest Gun Works, but major components are becoming harder to find.
Value: They are often found at very attractive prices on the used market ($300–$400), making them an excellent budget-friendly entry into the FN world.