FNX-9 Problems with Ammo, +P, +P+, or any issue

[Vulcan71]

Any problems using certain types of ammo: grain, bullet type, bullet design, +P, +P+, brand, in the FNX-9mm.


* Please list issues: stove pipe, jaming, magazine operation, feeding, case head, too much soot (dirty), etc.
** Please limit posts to the FNX-9.
*** Please limit posts to 9mm ammo.
**** Please keep on topic.

Thank you.

[djv38]

I have not heard of any issues with any +p ammo. I haven't even heard of any jams with any hollow points. FNX's come with relatively stiff recoil springs new, so the hotter +p ammo actually works better initially than non +p ammo.

[OneInTheChamber]

they say you can use +P ammo with no issues. the +P+ ammo they dont recommend because its too hot of a round and might cause a catastrophic failure of your pistol

[Jdunn6]

Could that be what happened here? I just took my FNX apart and unless I missed something last time I took it apart the back metal piece that holds the spring in place looks like its bent at an awkward angle. I've only shot Winchester's white box and about a half box of the +P+.

fnx2.jpgfnx.jpg

[djv38]

There's no way +p+ would bend that. It would likely bulge your barrel before it did that. Your barrel looks normal to me.

[Big Red]

I shot my FNX9 yesterday, no problems with 147 grain federal FMJ or buffalo bore 115 grain +P+.

[mattbeals]

Winchester Ranger SXT 127gr (maybe it's 124gr) +P+ fire fine. I don't like to shoot them much since their on the upper range of pressure limits. I mostly shoot 124gr NATO ball or 115gr Winchester White Box/115gr S&B. Early on I tried running some Remington UMC 115gr through it and had nothing but problems with FTE/FTF. I haven' tried it since. RBS 115gr ball was just as bad as the Remington UMC. Federal, Fiocchi, PMC/Blazer all seem to fire just fine. I think it was the Gold Dot +P JHP worked beautifully. Never had a problem with a JHP.

[Yotadude]

Has anyone had any issues with the 115gr FMJ 9mm Federal Champion 100 round boxes from Walmart? I bought 2 boxes and my FNX-9 is brand new I shot 150 rounds today and each mag I shot I had feed issues. I took the gun back to the store I bought it from and the guy working there told me it was probably the cheep ammo I was using. Is this ammo garbage? or is my gun faulty? or do i need to give it time to break in? I purchased some different ammo and will give it a try within the new few weeks.

[mattbeals]

It's weak ammo for how stiff the spring is. For break in you need strong ammo. I've had the best luck with the 115gr Winchester for consistency at Wally World. I had significant issues, FTFeed,FTE, with the Remington UMC when my fnx was new. On advice from a friend I switch to 124gr NATO (basically a +P ball) by Winchester and never had a problem again. Best advice summary from my experience and other posters here:
Lock the slide back for several days to weaken the spring a bit.
Cycle the slide back a few hundred times while enjoying your favorite show.
Run a few hundred rounds of good/strong ammo (like a +P). I've seen different comments about using 147gr standard loads too.

It's a super stiff spring even after 3,500 rounds for me. It's not a bad thing but it takes a while to break it in.

[Yotadude]

Thanks! I will try that.