Trigger disconnector question

Hickok45 · Sep 9, 2021

I'd like to reduce the pull weight in my FX9 and also increase reliability. My plan is to install an extra-power hammer spring for consistent ignition(I heard that 9mm needs more power from the hammer to consistently ignite, compared to 5.56) aswell as a reduced-power trigger spring for a lighter pull. Here's where my question comes in: most kits for reducing pull weight also include a lighter disconnector spring. 1st of all I don't really understand how that would even affect pull weight, but more over, wouldn't this decrease reliability by increasing my chances of slam fire or 2rd bursts? I figure I just won't install the new/lighter disconnector spring but I just want to make sure this is the right call. Thanks!

Oh also, and I figure the answer is yes, but: if after replacing the springs I still want an even lighter pull, would it be a bad idea in terms of reliability and safety to do some polishing?

joken · Oct 30, 2021

I'm no gunsmith but I've made enough mistakes in my life to have learned a bit. On my CZ's I replace the Hammer spring and sear spring and install a longer firing pin. It reduces the DA/SA trigger pull considerably. A stouter hammer spring will make it worse. I don't know what is available for your FX. I don't think the disconnector spring matters.

Member 34319 · Oct 30, 2021

The FX9, last I checked, takes standard AR15 triggers. I'd look into an aftermarket trigger for 9mms vs messing with the stock s trigger.

If I recall, these guys were having run away issues in the beginning. So they installed heavy triggers with stronger disconnects. Too light of a disconnect in a 9mm, can allow the mass of the bolt hitting the barrel when going home into battery to literally bump the disconnect and drop the hammer.

The disconnect spring needs to be weaker than the trigger spring. Otherwise the trigger would not reset when released as the trigger spring is what overcomes the disconnect and resets the trigger back onto the hammer sear. So, if you reduce the tension of the trigger spring and other aspects of the trigger and hammer mechanisms, you would in theory have to reduce the tension of the disconnect as well.

DirectDrive · Oct 30, 2021

Hickok45 said:
I'd like to reduce the pull weight in my FX9 and also increase reliability. My plan is to install an extra-power hammer spring for consistent ignition(I heard that 9mm needs more power from the hammer to consistently ignite, compared to 5.56) aswell as a reduced-power trigger spring for a lighter pull. Here's where my question comes in: most kits for reducing pull weight also include a lighter disconnector spring. 1st of all I don't really understand how that would even affect pull weight, but more over, wouldn't this decrease reliability by increasing my chances of slam fire or 2rd bursts? I figure I just won't install the new/lighter disconnector spring but I just want to make sure this is the right call. Thanks!

Oh also, and I figure the answer is yes, but: if after replacing the springs I still want an even lighter pull, would it be a bad idea in terms of reliability and safety to do some polishing?

Get one of these and call me in the morning... (Geissele SSA $169)

https://palmettostatearmory.com/geissele-super-semi-automatic-trigger.html?utm_medium=email&utm_source=daily_deals&utm_campaign=20211029&utm_term=afternoon&utm_content=593

Don't delay, they will sell out fast at this price.