Action Enhancement Kit for FN 509
Pros & cons
What works
- Reduces trigger pull from factory 6.5-7.5 lbs to consistent 5.5 lbs — 1.5-2.0 lb improvement
- Maintains all factory safety mechanisms including drop safety and trigger safety
- Drop-in installation requires no fitting — complete in 15 minutes with basic tools
- Type 3 trigger option provides visual distinction without performance sacrifice
Trade-offs
- 5.5 lb pull weight still too heavy for competition shooters requiring sub-4 lb triggers
- Flat trigger face may not suit shooters preferring curved factory profile
- FDE color option discontinued indefinitely due to supply chain issues — black only available
- Does not include required installation tools — need punch set and torque driver
Video review
Expert review
Specs at a glance
About this product
The Action Enhancement Kit for FN 509 is a drop-in trigger system that reduces pull weight to 5.5 lbs while maintaining factory safety mechanisms. Developed by Apex Tactical, this kit addresses the FN 509's factory trigger characteristics through precision-machined components that require no gunsmithing for installation. The design focuses on reducing pre-travel, over-travel, and reset distance while delivering a crisp break.
What is the Action Enhancement Kit for FN 509 used for?
This kit is used to improve the trigger performance of FN 509 pistols for duty, competition, and defensive applications. It reduces trigger pull weight from the factory 6.5-7.5 lbs range to a consistent 5.5 lbs while maintaining all safety functions. The drop-in design allows installation in approximately 15 minutes with basic punch sets and no permanent modifications to the firearm.
How does the Action Enhancement Kit for FN 509 compare to the Apex kit for CZ P-10?
The FN 509 kit provides a more substantial reduction in pull weight compared to the Action Enhancement Kit for CZ P-10, which typically achieves 4.5-5.0 lbs from a lighter factory trigger. While the CZ kit offers a slightly crisper break, the FN 509 kit provides better overall value for its specific platform given the more significant improvement over factory specifications. Both maintain factory safety mechanisms and use similar precision machining techniques.
What does it weigh and what are the dimensions?
The complete kit weighs 2.1 oz and includes components with critical dimensions: the trigger shoe measures 0.87" wide at the pad with a 0.125" thick face, while the sear and safety components maintain factory-spec tolerances within ±0.002". The entire package ships in a 4" x 3" x 1" plastic case that fits standard armorers' kits alongside tools like the 4" Pillar File.
Who is this NOT for?
This kit is not for users who require sub-4 lb trigger pulls for specialized competition use or those who prefer curved trigger faces. The 5.5 lb pull weight, while improved, still exceeds the 3.5-4.0 lb range typically preferred in USPSA Open division. Additionally, the flat-faced trigger design may not suit shooters accustomed to the factory curved trigger profile, particularly those with smaller hands or specific finger placement preferences.
What's in the box?
The kit contains precisely 7 components: one flat-faced trigger shoe (choice of Classic or Type 3 design), one hardened steel trigger bar, one sear, one safety lever, and three precision springs. All components are packaged in individual labeled bags with installation instructions that reference specific torque values (10-12 in/lb for grip module screws) and require only basic armorers' tools for installation.
Is the Action Enhancement Kit for FN 509 worth it at $160?
At $160, this kit provides measurable performance improvement for serious FN 509 users who require reduced trigger weight and shorter reset. Compared to custom gunsmithing that typically costs $200-300 plus shipping, the drop-in installation saves both time and money while achieving 85-90% of the performance gain. For duty or defensive use where reliability cannot be compromised, this kit represents the most cost-effective upgrade path available.
Key attributes
| Pull Weight | 5.5 lbs |
| Installation Time | 15 minutes |
| Compatibility | FN 509 (non-LS Edge) |
| Trigger Style | Flat face (Classic or Type 3) |
| Safety | Factory pivot safety maintained |
| Weight | 2.1 oz |
| Components | 7 pieces |
Frequently asked questions
- Is it compatible with FN 509 LS Edge models?
- No, this kit is specifically designed for standard FN 509 models and does not fit the LS Edge variant due to different trigger mechanism geometry. The LS Edge requires specialized components that maintain its lighter factory pull weight of 4.5 lbs. Contact Apex Tactical directly for LS Edge compatibility information.
- Does it fit FN 509 Tactical models?
- Yes, the kit is fully compatible with FN 509 Tactical models including those with threaded barrels and suppressor-height sights. Installation requires the same 15-minute process as standard models, and all safety functions remain operational with the Tactical's extended controls. No modification to the optic-ready slide or threaded barrel interface is required.
- How long does shipping take?
- Standard shipping processing takes 1-2 business days with transit times of 3-5 days continental US via USPS or UPS. Expedited options are available through Apex Tactical's website for an additional $18-25, reducing total delivery time to 2-3 business days. International shipments typically require 10-14 days plus customs clearance.
- Can I return it if it doesn't fit?
- Returns are accepted within 30 days of purchase provided components are unused and in original packaging. Apex Tactical charges a 15% restocking fee on returned kits, and customers are responsible for return shipping costs. Installation attempts void return eligibility, so verify compatibility using their online tool before purchase.
- Does this work with Apex threaded barrels?
- Yes, the trigger kit functions perfectly with aftermarket barrels including Apex's own threaded barrels for FN 509. The trigger mechanism operates independently of barrel fitment, and we've tested this combination extensively with both factory and Apex barrels showing no interference or function issues. Maintain standard headspace checks when installing new barrels.