I fixed my CZ-70 FTF problem

[weekender823]

First, a caveat – I am NOT a gunsmith and you choose this path at your own risk.


So, I bought a CZ-70 some time ago and got a sample that looks unissued. I have really wanted to like this pistol as a range toy, but like a lot of people I found it constantly failed to feed. Tried all kinds of ammo and typically had 1-2 FTF per magazine. The gun came with 2 mags and both had constant FTFs.


Then I tried reloading some rounds with a 77 Gr. RNFP cast bullet. Same problems but this time I noticed some scarring on the side of the soft lead of the cast bullets that jammed. I had three FTFs that had similar scars in the same area of the bullet. I tried some jacketed hardball and inspected the FTFs. Sure enough, there were similar faint scratches that I had not noticed before.




For my next range trip I took some of my reloads and a Sharpie marker. I marked a line down the brass cases and carefully loaded the magazines with the lines all facing up. This is what I mean:



The FTFs from this trip told me what I probably should have already known – the cartridges that FTF get jammed up against the ejector. You can see the ejector here:


So – the first thing I did I am going to recommend that you NOT do. I could feel some sharp edges on the back side of the ejector so I took a small stone to the sharp edges on the back side only. I avoided the front edges and the side profile. Another trip to the range showed small improvement, like maybe 1 in 3 magazines fired all 7 with no FTF. I think the next modification I tried would have fixed the problem all on its own but I included this just in case you need it.


The change that eliminated the FTFs for me was a magazine mod. I have two, so decided if I wrecked one I would still have one left. I wanted to see if I could direct the bullet away from the ejector and still hit the feed ramp. I took my caliper and measured the distance across the magazine feed lips and found one was .305 and the other was .310 inch.



I was concerned about damaging the feed lips with serrated jaw pliers so I dug out an antique pair of parallel jaw pliers with smooth jaws that I bought at a flea market. Choose your tool carefully.


To do this mod, retract the magazine follower and slip something through the side holes to hold it. Grasp the front half of the feed lip (left one in the picture) and carefully bend it outward from the right one until the gap was opened up .008 - .010 inch. Do that in small steps gradually increasing the force and checking with a caliper. After the gap is opened up and the lips are hopefully still straight bend the other lip inward until the gap is back to the original dimension.



Since doing this I have run about 200 rounds through the gun. Both mags are modified and they have been fed a variety of commercial and reloaded ammo. The FTF problem is gone and I am now happy with this little gun.


This fix is a sample size of one – your gun may be different. If some of you folks in the community have a CZ-70 and try this please post your results. Hopefully this is an easy fix that turns these pistols into the great shooters they ought to be!

 

[armoredman]

I had two CZ70s in the past and found them really neat guns with HORRIBLE trigger pulls. I even carried one as a BUG doing armored work. Nice to see you fixed your issue!

 

[wiscoaster]

My VZ-70's FTF issue was also magazine related.

Actually the mag with the extended pinky rest in the photo was the worst of the bunch.

I had hopes of this being my shoulder-holster carry gun, but it's going to just remain a range toy. Obviously it's no longer a collectible.

 

[Dibbs]

Note to self: Pick up a couple extra mags, in case this jam issue arises...

 

[film495]

I have one of these and some ammo is just a no go - for feed and eject issues. Euro seems to run no issues, usually use Fiocci - and some Geco, but the Geco I only run 5 deep in the mags. When you load the rounds into the mag, notice how the first one sits and how each one you add, the nose seems to sit a touch lower, some ammo will sit low enough with the nose down, and jam into the front of the magazize on feeding; usually one of the first couple in the mag and if you make it past that they run Ok the rest of the way.

My guess is that gouge in the lead is from the bullet hitting the front of the mag as the round is stripped. You could in theory, polish that up or stone it smooth, so the rounds do not catch on it, but - my experience with my CZ-70 has been some ammo will sit in the mag with the nose dipped down, and then jam into the front of the mag and stop there, or bounce the nose up too high, and jam above the chamer.

I have 3 mags for mine, and they all work good. It is possible youre mags had a little bend to the lips, maybe they were dropped - and your work here, was more straightening them out, so when the bullet strips, it hits the ramp, and not the front of the mag.

Again, this was just my experience, like you - with my one CZ-70, and US ammo did not make it happy. The rounds do not sit correctly in the magazines, I think the extractor groove is cut a touch different on the cases, than 7.65 Browning ammo, and it gives the catridges a propencity to nosedive when feeding and cuases FTF issues.

I haven't had any feed or eject issue now in I don't know how many hundred rounds - and oh, keep an eye on the pin that holds the ejector/slide stop in place. On mine eventually the mechanical action of the slide stop will loosen the pin a touch, and I just check it when I clean mine and if that arm has any side to side wiggle, I give that pin a whack with a punch, and it is good for another 200-500 rounds.

Really, like my little CZ-70 a lot. I had to fight with it for a while doing this and that, but - just a really nice little firearm the works great.