CZ 24 Jamming

[Niccolo]

I’m new to the forum.  I have a CZ 24 in 380 that jams every round.  The spent shell leaves the breech and jams against the next round.  Had a gunsmith repair the magazine, but no effect.  I also replaced the extractor spring.  Nada.  Any suggestions?  Thanks. 

[Palmetto Marsh]

Ammo brand/type sometimes could be the cause on these CZ 24's .. what brand are you using? 

[Niccolo]

Thanks.  Fiochhi and Magtech.

[armabill]

I did some tests awhile back, it may help.

                                                       CZ 24 .380 ACP TEST FIRING

                                                      Chamber Inner Diameter: .378

95 GRS                                                                                     FPS                                          RESULTS

Fiochhi: FMJ (round nose)              *.373 diameter .971 length     960                                Fired and stove piped 5x
Geco: FMJ (round nose)                 *.370 diameter .963 length     985                                Fired and ejected ok 5x
Winchester: FMJ (flat nose)            *.372 diameter .940 length     955                                Fired and ejected ok 5x
Remington UMC: (round nose)        *.371 diameter .969 length     955                                Fired and ejected ok 5x

90 GRS

PMC Bronze 380A: (round nose)     *.371 diameter .971 length      961                                Fired and ejected ok 5x

*Diameter measurement is taken at the loaded case mouth not on the bullet.

**All tests were fired with 6 rounds from each group. Each groups first round was manually chambered
with no problems. Subsequent rounds were automatically fed and chambered ok, except where noted
above.
Updated: 2-10-2020

[armabill]

I didn't have any MagTech ammo.

[Niccolo]

Thank you so much for this information.  Very kind of you and much appreciated.  I’ll try the ammo you have tested and see if it works.  Niccolo

[armabill]

Sounds like a plan.

[Niccolo]

Tried PMJ - got two consecutive rounds then a jam.  It isn’t stovepiping.  What happens it that the spent shell is extracted maybe a quarter inch, then it runs aground, so to speak, on the next round.  It seems to me that the next round is riding just a little too high for the spent shell to clear.  I had some success by closing the magazine’s lips, but they soon open again.  Any ideas?

[armabill]

I assume that you mean PMC ammo. Have you tried another magazine? What is the make of the problem magazine?

[Niccolo]

Yes, sorry, PMC ammo.  The magazine came with the pistol.  No manufacture mark on it.  I have tried to find another magazine, but they are scarce right now.  Triple K has them on back order, waiting for demand and steel they say.  The one I have was pretty beat up when I got it, but I’ve had it restored by someone who knows vintage magazines.  I think it is the magazine, because when I played with the opening I could get five shots off without issue.  But that would only work for a while.

[armabill]

Triple K magazines are hit and miss. If you can get an original factory magazine, that would be better. It might cost more but worth it. They come up on Gunbroker every once in awhile. Also, gun shows are a good place.

I think that you are right to suspect the magazine. The reason that I did the tests was that some guys at my club were having issues and asked if I could use my CZ 24 for an ammo comparison.

[Niccolo]

Thanks for the tip on factory vs Triple K.  I’ll look for one and see if that solves the problem.