WHAT'S IN THE KIT:
- 1 - Custom Lighter Sear Spring
- 1 - Custom Lighter Disconnector Spring
- 1 - Custom Lighter Striker Spring
- 1 - Custom Lighter Striker Block Spring
FN 509 Trigger Spring Kit
Designed by combat veterans, this custom trigger job will reduce your trigger pull from a factory ~7.25lbs to a modified ~4.25lbs, offering a substantial 40% reduction. Experience a lighter, smoother trigger pull and improved reset, making this upgrade a must-have for anyone seeking optimal performance from their FN 509.
Our FN 509 Trigger Spring Kit corrects issues with the factory trigger and is an essential upgrade for enhancing accuracy and performance. Ideal for those seeking competition-level performance, this kit is a significant improvement over the factory setup.
Upgrade your firearm with the best aftermarket parts and experience competition-level performance with our FN 509 Trigger Spring Kit!
FN 509 Resources:
If you're 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.
Drop Tested and Approved:
FN 509 Trigger Spring Kit is drop Tested according to SAAMI Standard Z299.5 rating (12" & 48").
Tested and Approved:
The FN 509 Trigger Spring Kit has been tested repeatedly to ensure reliable operation and safety.
ATTENTION:
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.
M-CARBO for the WIN!!!
I purchased my FN 509 Midsize about 2 years ago. It's a fantastic firearm, but had room for improvement in the trigger department. The trigger wasn't as heavy as some others have claimed, but my trigger pull was averaging about 6 lbs. Honestly what bothered me the most is that the trigger pull was inconsistent. Sometimes the pull would be 5.5 lbs, and other times, the pull would be 6lbs; or somewhere in between.
I knew that this M-CARBO spring kit would be an awesome upgrade, as I've used their kits in past with other firearms. Shipping was fast, and instructions were clear and concise. Their installation video covers everything, and is really easy to understand. I managed to get this installed in about 30-45 minutes without too much hassle.
Once installed, my trigger pull went down to a consistent 4lbs 2 Ounces. The trigger pull is much cleaner, and a large amount of the spongy grit has been removed. The reset remains the same, which some people might not like as many prefer the super short reset. However, I believe that the is a fantastic upgrade to the stock factory trigger, and I highly recommend it to others!
I could not be happier, buy this for your FN 509 without hesitation!
Quality parts
Tried many FN509's over the years and always walked away because of the dreadful triggers. When I saw the trigger and striker had been redesigned for the LAPD trials, I took a leap of faith and ordered the FN509 MRD LE package and the MCARBO spring kit.
Surprise! The trigger in the new gun was not bad! The initial take up was not bad and the break was nice with a crisp but not crazy heavy wall. I only installed the MCARBO striker safety block spring, which made the trigger perfect for me, lighter take up with no grit.
I can't speak for the rest of the spring kit because I didn't need it, but it was worth the price to make my great gun absolutely perfect.
509cc edge
This spring kit was an absolute game changer! I highly recommend this kit. The install video and printable instructions are very detailed and easy to follow! My pistols plus optic is pushing 2000 and it has the worst trigger Iv ever felt in my life, seriously it upsets me and because of this it will probably be my last FN purchase. I thought about selling it but it’s probably the best flattest shooting striker fire pistol and best shooting compact pistol Iv ever shot so i tryed to just pour more money into a stupid expensive pistol to make it the way it should have come from factory at this price. This spring kit changed every aspect of my trigger pull. I swear on everything this cheap little upgrade ALONE lightened the pull took all of the gritty dirty feeling take up out put a much more defined wall in the pull and a nice break on it. I’m blown away! And who knows maybe the break feels better because the take up doesn’t feel gritty as hell anymore and it’s lighter to make it break I don’t know. All I know is these springs alone have gone above and beyond my expectations 100%. I had polished my sear prior but only what I could reach with the assembly still in the frame, while I had it out I polished every piece that I could as well. Anyways 10/10 +10 recomended, by the way bad A packaging!
The 509 spring kit is awesome
I installed it in my FNS 40 LS, the video direction make installation very doable.
The trigger pull is much smoother and lighter, I am very happy with the results
Light strikes
The kit vastly improved the trigger but had 2 light strikes in 50 rounds. The light strike rounds fired in my other gun fine. Would go a tad heavier on the striker spring. Do not know what the spring rate is. Accuracy was awesome. Almost there.
A must upgrade for the 509
The OEM 509 trigger was kind of mushy and especially on the reset. I was not happy when shooting this handgun. I put this trigger spring package in and what a difference!! Trigger pull was crisp and the reset was way better. The video is thorough and explained nicely. It makes the install extremely easy and done in less than an hour. Plus it was nice to do some deep cleaning with the gun apart and with the video paused.
easy day
Installed this along with the upgraded striker, was an easy day though I thought it might mimic the P365XL upgrade, much easier and feels and works flawless. Thanks MCARBO for great install videos
Fn 509 spring kit
I am pleasantly surprised with the difference your fn 509 spring kit has made. I have a compact version and absolutely love the ergonomics of this pistol, but the trigger weight is way too heavy. Your kit has made this pistol fantastic. Thank you
Hello, does it works with the FN 545?
Thanks
I’m also asking about the fn510 will the 509 kit work? If not please make a kit for a 510. Thank you.
I’m also asking about the fn510 will the 509 kit work? If not please make a kit for a 510. Thank you.
I’m also asking about the fn510 will the 509 kit work? If not please make a kit for a 510. Thank you.
I’m also asking about the fn510 will the 509 kit work? If not please make a kit for a 510. Thank you.
I’m also asking about the fn510 will the 509 kit work? If not please make a kit for a 510. Thank you.
Will you be getting a spring kit for the new 510?
If this lighter spring kit is used with the Apex striker, which is heavier than the Mcarbo titanium one, would it presumably lessen the chance of light strikes?
Not compatible, apex striker is to damn heavy! But m carbo titanium striker is well titanium super light and strong so you will have better results.
Answered by
Patrick M /
November 28, 2023 4:42 PM
do your spring kits work with apex triggers like for the M&P or the FN 509 please let me know thanks also i was wondering if you fully polish the spring kits and other parts whether it be for a j-frame or M&P whatever the cause can you lower the trigger pull to get to that low end of the plus or minus 1 pound or possibly lower im looking for the lowest i can get on my double action only j-frame and other models please let me know thanks please get back as soon as you can thanks
In previous installations you’ve sanded and polished the striker block (example M&P Shield), will doing so with the 509 striker block be helpful and can be done or very bad idea?
It can recomended all depends if it is need it and how much polishing you will do.
I see it works with 509C, doesn't "specifically state" 509M - just want to make sure before I order along with the striker.
Yes, these parts will work in the 509M!
Will this fit the 509 Edge Long Slide?
GerryM January 6, 2023 6:03 AM
It also functions in 509C, 509C Tactical, and FNS Models, but I don't think we have tested it on that exact model; if the internal is the same and only the barrel and slide are longer, it can work.
Is this trigger spring kit compatible with the apex tactical trigger kit?
We only test with OEM parts; We can't say if it will work with APex
We only test with OEM parts; We can't say if it will work with APex
We only test with OEM parts; We can't say if it will work with APex
We only test with OEM parts; We can't say if it will work with APex
is this the same striker spring that comes with the striker kit?
November 29, 2022 8:54 AM
Yes it is! We include it at no extra cost with the striker to ensure safe and proper function of the lighter-weight Titanium Striker. If you choose to purchase both the spring kit and striker, then you will end up with a free spare striker spring.
Does the FN 509 Trigger Spring Kit work on the FN 509 Compact?
functions in 509C, 509C Tactical, and FNS Models
Is your spring kit compatible with the Apex trigger system? If so, what would be the expected difference combined?
We do not guarantee our spring kit with any other aftermarket parts, including the Apex Trigger System. We are, however, working on new upgrades for this model ourselves, which gives us better control to confirm compatibility! Please send an email to help@mcarbo.com if you would like to be notified directly for any new MCARBO upgrades for the FN 509!
Any options for the new 502 Rimfire version or any chance some of the 509 kit would help the 502 SAO 5 lb trigger?
We haven't tested any of these springs in the 502, but if you send us an email to help@mcarbo.com we will save your contact information along with your product request to our idea log!
It says it will fit FNS also so would it fit a FNS 40? If it does I would rather order order the same time for my 509T
I am sorry for our delayed response in the Q&A section. Yes this spring kit will work for your FNS 40!!
I am going to install the trigger spring kit in my FN 509 LS Edge. Besides the striker and striker block, what else would you suggest I polish? Really looking forward to the installation. The factory trigger is really "gritty". It was disappointing for a fairly expensive pistol. Thanks for the help.
Bob Turner
RWT January 10, 2022 3:17 PM
Each gun is a little different, I would look for any parts that show witness marks (wear) such as the trigger bar, if it shows signs of rubbing on the frame or another part, you can polish up that area to improve the feel. Use caution, to much polishing can be a bad thing. So take your time and do little by little.
Does this trigger spring kit function with my FN Five-Seven? If not, do you offer one for it?
We have not tested it for the 5 7 model so i would not advise trying it. Currently we do not offer one for the 5 7
Any reason this would not work with an Apex Tactical FN509 trigger? Thanks!
November 19, 2021 4:17 AM
I have been using this and have been pleased w/ the performance. I recently upgraded to the Apex Tactical performance trigger which includes a new sear. It feels that the strike seems weaker. Should I put back all of the OEM springs back or perhaps just the sear spring?
Thank you for contacting us, I believe the issue is with the APEX striker combined with our striker spring. If you would like to maintain the APEX striker I would swap back to the Factory striker spring, or you can swap back to the factory striker and maintain our spring. The difference in weight between the two strikers combined with the lighter striker spring can lead to light strikes, especially with reloaded or steel cased/surplus ammo.
Answered by
/
December 16, 2021 11:58 AM
If I bought this kit for the 509/c/t and only installed, let’s say just the striker firing pin spring and striker block spring to start? Would I see any potential benefits? Less grit? Less drag?
Hey Brother,
You will definitely see a reduction although we cannot give you a definitive amount. In regards to the smoothness and drag. So long as you polish some of the parts, you'll be good to go!
Will this function in the FN 509 LS Edge?
Hello, our FN 509 kit is compatible with all FN 509 models, including the LS Edge.