Wanted to get some advice.. I got a FNX-40 earlier this year and so far really like it. Took it out three times so far firing a few hundred rounds through it.
The last time I took it out it was working great for two magazines and then I started getting double feeding. The gun would fire, a new round would load into the chamber but another round would "sneak" up behind it. Obviously it won't fire and it could be dangerous... Any ideas what could cause this? It happened with two shooters and two different magazines. I was using ammo I hadn't used before, Prvi Partizan. It is brass non-corrosive ammo. I didn't see any review issues with the ammo so I figured it'd be good. This doesn't really seem like a ammo issue though.

Any thoughts? I plan on carrying this pistol when my CCW comes through so I'd like it to be reliable. If its just a ammo thing, no biggie, but if this seems like a repair worthy issue I'd like to get it in ASAP.

~Edit - oh and with this ammo the casing was ejecting upwards and towards the shooter... That doesn't seem normal.

Go back to the range with ammo you know that works. If it works then you obviously know it was the ammo!

Maybe, but I like to think that pistols should be able to shoot most ammo, and like I said, not sure if it is actually a ammo issue, since its double-feeding...

But it is a valid troubleshooting method. You may have a problem with your pistol that only shows when shooting that ammo.

Yeah I suppose. I guess I was just curious if other people have had similar issues and possibly if caused by ammo. Just seems like a odd thing to be caused by bad ammo.

Unless you're putting 9mm ammo in a .40cal gun, I highly doubt this is an ammo issue, IMO. Sounds to me like perhaps the feed lips on the mag(s) are out of spec, i.e. spread too far apart.

With some new mags, getting in that last 1-2rds can be a bear & if a mag loading tool isn't used, it wouldn't be too hard to spread the mag lips, IMO.

My .o2

It sounds as if the top cartridge is escaping the magazine while the slide is recoiling to the rear, and when the slide comes forward, it's picking up the next round in the mag and pushing it forward, while the first cartridge is already heading into the chamber.

If this is the case, it points to insufficient friction between the cartridge and magazine.   The magazine lips or ammo may have gotten oily, or the magazine springs may be going weak.   The latter case usually causes doublefeeds when you get toward the bottom of the mag and the spring is exerting less tension on the rounds.

Now that I think about it it was only the last few rounds in a magazine that were having issues. Magazine issues definitely sound like the problem I'm having. I think what you describe is what is happening...

I ran across a post somewhere that mentioned FNX mags made before December of last year had some problems, I wonder if this is related. I'll have to contact FN and see if they had a mag recall.

Thank you so much for these last two responses, they were very helpful and exactly what i was looking for.

FN pistol mags are pretty bad...  Ask me how I know.

I am not a fan of mags for the FNP. I had one and FN had to exchange them for weak mag springs. That was a long standing issue on gun forums a few years ago. Until the day that aftermarket mag springs are made for the FNP/FNX series, I'd avoid them, personally.

I know that doesn't help you, though.

Clean the guna nd lube it well. Try a different ammo. And, pay attention to see if it only happens with a certain magazine.

+1

If that doesn't work send it back to FNH.  Good luck.

Thanks for all the great responses. I actually called the service department not long after I wrote this and they want me to send the gun in. The guy I talked to said this shouldn't be happening and since its a bit dangerous wanted to get it in right away. So I'll be sending it in tomorrow (I'm such a horrid procrastinator, I should have sent it in already, but I've never mailed a handgun before, so apprehensive about sending it out).

Avoid their magazines or just the spring? Do you have a recommended replacement? Like I said in my prior post I'm going to send it in, but if I continue to have issues a replacement spring is a simple fix if that is what it is.