I recently picked up a new IWI Jericho 941 FS (their mid size model, 3.8" barrel).



It has a better "out of the box" trigger than any stock (non Custom Shop/race gun) CZ that I have ever owned or handled, which
I'm guessing is because it's based on a Tanfoglio design, with much better hammer/sear geometry.  It is capable of shooting very good groups in my hands, no issue there.  However, and it's very intermittent, it will have a failure to eject, leaving the spent case laying in the ejection port, which means dropping the mag and hand cycling the slide to clear it.

It does not seem to be ammo dependent or magazine dependent as I have 7 mags for it and have tried 5 different types of 115, 124, 147 ammo, both FMJ and JHP.

Visually I don't see anything wrong with the extractor or ejector, though I have nothing to compare them to.  I have thoroughly cleaned it before and after firing it, paying very close attention to the extractor, and even popped the extractor out and cleaned it's machined recess, just to be sure.  I do have some doubts about the extractor spring, not that is seem weak, but it may be a bit deformed.  

Any thoughts on this?   I have tried my g00gle fu, and have found a couple of posts here and there about extraction issues, but none with a definitive answer.

*UPDATE*

Well I purchased a new extractor from Numrich and installed it earlier this week.  Just back from the range after putting 200 rounds through my 941.  100 115gr. fmj Blazer Brass, 50 MEN 124gr. NATO fmj, and 50 Remington Golden Saber 147 gr JHP.

Not one failure, and the pistol's ejection was much stronger than in the past.  The original extractor looked like it had been gnawed on by rodents with tungsten carbide teeth.  I decided to just do the repair myself and save the shipping time to and from IWI US.  Piece of cake.  I am now a very happy camper.

The pistol has been accurate out of the box, though it does seem to prefer 124 and 147 grain ammo over 115.  Much tighter and more consistent groups with the heavier loads.

Hope you get it figured out, she’s purity.

My Full size Single action 941 that I got a year or 2 ago has the the same issue, maybe once in every 200 rounds or so I will have a casing stove pipe in some way. I have changed the extractor spring and the recoil spring for new Wolf units but not much has really changed unfortunately. I have a new extractor some where that I ordered and when ever I can find it I will install it as well.

Kinda of a bummer because I really like shooting the gun . I would do an ejector swap if it wasn't such a process and if the parts weren't so expensive.

I had the same issue with the same era (IWI, Harrisonburg PA) 941F, full size model.  Once I got a few hundred rounds through her it went away and functioned perfectly.

I have 606 rounds through it now.  On the last range session it failed to eject two times in 200 rounds.

Better, but still unacceptable for anything but a range toy.  The trigger has gotten better though.  I have a new extractor and spring coming for it.  Will see how that pans out.