i emailed apex and they didnt respond, so i figured id see if anyone had a similar issue. i installed the apex action enhancement kit, apex striker, and the mcarbo springs kit, but i left the factory striker spring in. the pull is 5# 8oz to 6# even and it is not a crisp break at all. the factory trigger was heavier, but a nicer and cleaner break (with stock springs, havent tried it with mcarbo springs yet). ive installed many trigger kits in the past and i turn wrenches for a living, so im very confident it was installed correctly.

any ideas?

finally got ahold of apex and they said the mcarbo springs arent compatible and will cause issues. i switched back to the factory springs and the trigger pull is the same but 1/2# heavier.

No experience with the Apex triggers for FNS pistols, but I have a buddy with at least a couple FNS models and he put the Apex triggers in them and swears by them.  He says the pull weight didn't drop (like it will on an M&P) but it did drop a pound or so and got really smooth/crisp vs. the factory trigger.

I like enough things about the FNS to carry the (sometimes) in spite of the poor trigger as compared to some of my CZ pistols or the M&Ps with Apex triggers.

One other thing, I did install the Apex strikers in two of my FNS slides.  It did (to my finger's opinion anyway) change the trigger pull for the worse, temporarily.  The triggers had broken in to be pretty crisp, but still heavy.  After installation of the Apex strikers they were rougher and the reset to striker release distance increased.  I pulled them back out of the slides and compared them to the factory strikers and the dog legs (part that sticks down to interact with the sears) was longer on the Apex strikers vs. the factory strikers.  I did some stoning/polishing on both of the Apex strikers on the bottom (small amount removed) and the front (just polished.)  When I reinstalled them the one in the long slide was perfect again.  The one in the Compact was intermittent (on both reset to striker release feel and crispness) but the longer I dry fired it the better it got.  After several minutes of dry firing it was good on 8 or 9 trigger pulls out of 10 and I figured it would eventually wear in "perfect" again after more firing/dry firing.

Good luck with yours.  Hopefully it'll wear in and smooth out for you.

thanks for the info. i also noticed that the apex sear was longer than the factory one. ill start swapping parts in and out to try and narrow down what the exact issue is.

swapped the factory sear in and left the rest as it was. pull got heavier and it wasnt any cleaner.

edit: apex offered to send me another kit to try out. ill update once i swap it in.

I was thinking of taking my 509C in for an Apex trigger, now I'm not sure.  I was hoping to get a lighter pull off of it.

I'd be interested to know what the results are if you put the Apex sear back in, use the mcarbo striker spring, leave the rest as-is and dry fire about 200 times.

leaving all the apex parts in and swapping to all of the mcarbo springs brought it down to about 5# even but not a clean break at all. i havent had time to swap the whole kit to the new one yet, its still on the first one.