FN FNX

FNX-45 Tactical Specs: 15+1 in .45 ACP

The FNX-45 Tactical runs a 5.3” cold-hammer-forged barrel threaded at .578×28 — the standard .45 ACP suppressor thread pitch. Overall length is 8.2”, height is 6.0”, width is 1.47”, and weight is 33.6 oz. unloaded. The 15+1 capacity in .45 ACP is achieved through a double-stack magazine — the grip is correspondingly large, but the interchangeable backstraps (small, medium, large) help fit a range of hand sizes. The slide is milled at the factory for a MRD (mini red dot) optic, with an FN-specific mounting plate that interfaces with Trijicon RMR, Leupold DeltaPoint, and other common footprints.

FNX-45 Tactical Suppressed: The Primary Use Case

The FNX-45 Tactical is the factory-configured .45 ACP suppressor host. The .578×28 threaded barrel accepts any standard .45 ACP suppressor, and the suppressor-height Trijicon night sights provide a usable sight picture over the top of most cans. Since January 1, 2026, the NFA $200 tax stamp has been eliminated, making suppressor acquisition straightforward. Running .45 ACP subsonic loads (230 gr. at approximately 830 fps) through a quality suppressor on the FNX-45 Tactical produces some of the quietest centerfire pistol performance possible — .45 ACP is inherently subsonic, requiring no special subsonic ammunition for quiet operation.

FNX-45 DA/SA Trigger: What to Expect

The FNX-45 uses a traditional DA/SA trigger with an ambidextrous decocker/safety lever. The first shot from a decocked hammer is DA (approximately 12 lbs.); subsequent shots are SA (approximately 5.5 lbs.). The SA trigger is excellent for a production pistol — crisp, with minimal overtravel. The ambidextrous controls make the FNX-45 fully functional for left-handed shooters, which is unusual in full-featured service pistols. Shooters coming from striker-fired guns will need to adapt to the DA/SA manual of arms, but the payoff is the SA trigger quality for precision shots and the additional manual safety layer provided by the external hammer.

FNX-45 vs. HK45 Tactical: Premium .45 ACP Comparison

The FN FNX-45 Tactical and H&K HK45 Tactical are the two premier suppressor-ready .45 ACP pistols on the market. The HK45 Tactical has a slightly better stock trigger and HK’s legendary build quality at a significantly higher price. The FNX-45 Tactical offers more capacity (15+1 vs. 10+1), a factory optics-ready slide, and a lower price point while delivering comparable build quality. For most shooters, the FNX-45 Tactical’s capacity advantage and lower price make it the better value. For shooters who prioritize HK’s specific trigger feel and don’t need the higher capacity, the HK45 remains compelling.

FNX-45 Tactical Optics: What Fits the Factory Cut

The FNX-45 Tactical’s factory slide cut accommodates the Trijicon RMR and compatible footprints via the included mounting plate. The full-size slide provides a stable mounting platform that doesn’t flex under recoil the way smaller pistol slides can. Running a full-size red dot on a suppressed .45 ACP platform creates an exceptional close-to-medium range system — the combination of large-caliber suppressed fire and an electronic sight is particularly effective in low-light conditions where the red dot provides immediate target acquisition without requiring a precise sight picture alignment.

Shop FN FNX-45 and .45 ACP Pistols at Impact Guns

Browse the full FN America lineup including the FN 509 and FN SCAR at Impact Guns. For .45 ACP ammunition, visit our .45 ACP ammo page. For suppressors, see our suppressors page.