• Reduce your trigger pull from 7.25lbs to a modified 4.25lbs (Average results can vary up to +/- 1lb)
  • Improve accuracy and overall FN 509 Performance
  • Solid 40% Trigger Pull Reduction!
  • Custom FN 509 Aftermarket Trigger Upgrade!
  • Highest Quality American Spring Steel ASTM A228 Music Wire
  • FN 509 Trigger Kit includes a Custom Lighter Sear Spring, Disconnector Spring, Striker Spring and Striker Block Spring
  • Protected by the M*CARBO 100% Lifetime Guarantee
  • Made in the USA!
  • Fast Same Day Shipping!

FN 509 Trigger Spring Kit

  • Custom Lighter Sear Spring
  • Custom Lighter Disconnector Spring
  • Custom Lighter Striker Spring
  • Custom Lighter Striker Block Spring

Custom FN 509 Trigger Job to reduce trigger pull from a factory 7.25lbs to a modified 4.25lbs, giving you a 40% FN 509 Trigger Pull Reduction! Best FN 509 Trigger Upgrade for Increased Performance.  Lighter and Smoother FN 509 Trigger Pull and Improved FN 509 Trigger Reset. Custom FN 509 Accessories by Combat Veterans! Best FN 509 Aftermarket Parts to get the Most Performance out of your FN 509 Pistol! 

The FN 509 Trigger Mod is a must have for FN 509 Aftermarket Trigger Upgrades! Improved Accuracy with Custom FN 509 Trigger Upgrade designed by Combat Veterans! Best way to improve the FN 509 Trigger with Custom FN 509 Trigger Spring Kit by M*CARBO!  Correct FN 509 Problems with Factory FN 509 Trigger.

Custom FN 509 Trigger Upgrade to Improve Performance and Accuracy! If you have ideas for more FN 509 Accessories send us an email.

Best FN 509 Upgrades for Competition Level Performance!

FN 509 Owners Manual & Exploded View:

If your getting the FN 509 Trigger Spring Kit, then you might find the following FN 509 Resources useful in further enhancing your firearm. Download the FN 509 Owners Manual to plan your next firearm project.

    M*CARBO No Hassle 100% Lifetime Guarantee:

    The FN 509 Trigger Spring Kit is protected by the M*CARBO No Hassle 100% Lifetime Guarantee.

    Drop Tested and Approved:

    FN 509 Trigger Spring Kit is built with M*CARBO ASTM Spec Springs that will offer a perfect trigger pull reduction with an unlimited drop test rating (3", 6", 9" & 12"+).

    Tested and Approved:

    The FN 509 Trigger Spring Kit has been tested repeatedly with numerous brands of ammunition to ensure reliable operation and safety.

    Veteran Owned and Operated Business:

    American made FN 509 Trigger Spring Kit designed and manufactured by Combat Veterans. We will donate a portion of your purchase to the Military Foundations we humbly support.


    You must be 18 yrs of age to purchase. We advise that all parts purchased from our inventory be installed and inspected by a qualified gunsmith. Modifying your weapon may be prohibited in your state. Do not modify your sear or hammer engagement surfaces, with or without the FN 509 Trigger Spring Kit. Before installing please be sure to check all local state and federal laws. By installing this part you agree to take full responsibility for any and all legal, health and warranty consequences that may be incurred.

    Overall Customer Rating of 48 Reviews:

    Must buy for the 509!!

    Great product with an immediate noticeable difference! I would highly recommend getting this if you have a 509. Can’t beat it for the money. Trigger pull and response feels so much better. The videos for install was great and easy to follow.


    Watch Video Carefully

    Please watch the entire video without skipping any parts or you may end up like me who spent a good two hours trying to correctly insert the sear housing back to where the pin could become flush on both sides of the pistol grip again. Overall, this kit combined with the synthetic grease for 2 bucks, is 100% worth the small cost to make the stock trigger better. No more grittiness in the build-up to the trigger pull, the pull itself is not so heavy anymore, and even the reset feels cleaner. Highly recommend this product if you don't want to drop 150+ bucks on an apex trigger.


    This kit is very easy to install. The hardest part was driving out the roll pin. I don’t have a trigger pull scale, but it feels as though the weight of the pull has been cut in half. The install video was very informative and helpful. This is a must have for the 509!


    Quick install, video is easy to follow.

    Quick and easy, and makes a HUGE difference! Cant wait to hot the range tomorrow

    product works great; installation video is invaluable

    I've dropped in the new springs and had a successful range class outing. My shot groups tightened up and time to acquire target on followup shots....since the trigger pull is is lighter, one may not pull off the target with the harder trigger squeeze. The video is well done and helps one have the confidence to do a self-install. One needs nimble fingers and good eyesight to reassemble the sear assembly. One difference with my stock spring between the two pins is the loops are the same size and snug, so I had to position the spring into place from the rear and not obstruct the loop with the needle nose pliers. I also found the greasing tip to hold spring/pin in place useful, as well as greasing the trigger against the frame. I've also had a friend shoot the fn509 with the new springs and also noticed a positive improvement for a cleaner break while holding on-target. Anyone pulling shots left or right with the factory kits should insert this kit.

    Number of questions: 0