Action Enhancement Kit for FNS

If you own an FNS pistol and wish the trigger felt cleaner and lighter straight from the box, this drop-in kit is exactly what you need. Designed by the same folks who pioneered the aftermarket FNS trigger system, this component addresses the mushy take-up and long reset that many factory triggers suffer from. It replaces the stock trigger and sear with a patent-pending design that reduces pull weight to around 5.5 lbs, shortens pre-travel and over-travel, and gives you a crisp, consistent break every time. Best of all, it drops right in with zero fitting—no filing, no stoning, no trips to a gunsmith. If you want a better shooting FNS without the headache of permanent modifications, this is the straightforward fix.

Will this fit my FNS?

This kit is a direct drop-in for the following FN models:

• FNS-9 (all generations)
• FNS-9 Long Slide
• FNS-40 (all generations)
• FNS-40 Long Slide
• FN 509 series (with included adapter sleeve – verify with your specific model)

Note: Not compatible with FNX or FNP series pistols. If you’re unsure, give us a call—we’ll help you confirm fitment before you buy.

Key features

• Drop-in design: No fitting, filing, or permanent modifications required. Open the box, swap the parts, and you’re done.
• Reduced pull weight: Factory triggers often run 6.5–7 lbs; this kit brings it down to a consistent ~5.5 lbs, making it easier to shoot accurately without sacrificing reliability.
• Shortened reset: The trigger resets noticeably shorter and more positive—you’ll feel the click immediately, which helps with fast follow-up shots.
• Center-mounted pivoting safety: Maintains all factory safety values, so you can carry or compete with confidence. No unintended discharges, just a cleaner pull.
• Patent-pending design: Uses a unique sear geometry that delivers a crisp break without the gritty creep common in stock triggers.

Install difficulty: 2 out of 5

Tools needed: Punch set, small hammer, and a #2 Phillips screwdriver. No special armorer tools required. If you’ve ever detail-stripped a polymer striker pistol, you can handle this in about 20 minutes. We recommend watching the install video linked on this page—it walks you through the two tricky steps.

Frequently asked questions

Will this work with my carry gun?

Yes. The kit keeps all factory drop-safety and trigger-safety functions intact. Many of our customers run it in their daily carry FNS without issue. That said, always test your firearm with defensive ammunition after installation to confirm reliability.

Do I need to replace the striker or springs?

No. Everything you need comes in the box—trigger, sear, and all necessary components. The kit is designed to work with your factory striker and springs. If you want to fine-tune further down the road, you can add an aftermarket striker spring, but it’s not required for the ~5.5 lb pull weight.

What if I mess up the install?

We’ve got you covered. This kit comes with a full lifetime warranty against defects, and we offer phone and email support during business hours. If you run into trouble, just reach out—we’ll help you get it sorted. If you’d rather have a pro do it, any competent gunsmith can install it in under 30 minutes.

Shipping & warranty: Free shipping on all orders over $75. Every kit is backed by a lifetime warranty against manufacturing defects. If it breaks,