[agony]

Recently got a transitional CZ 85, dated 1994. I am the second owner.
Great pistol, and expected it to run like my CZ 75b.

However, I ran into a problem.

I put 250 rounds through it today after a proper clean and lube. The ammo was factory WIN white box, and 115gr handloads.

With both types of ammo, the slide would occasionally lock open....even though the mag still had ammo in it. I used different mags, and it occured in all of them. There was no pattern to this.

My theory is either:
1- I need a new recoil spring.
2- I may be very very slightly touching the lefty slide release with my thumb (I shoot lefty).

Any suggestions from the choir?
:)

[44rem]

Hi agony,
I had exactly same problem with my CZ 85 Combat, but only with factory ammo
(my cast lead reloads < 920ft/sec worked OK). I'd solved problem with my limited skills.
Take slide out, insert slide stop/relies back in place, play with left and right levers.
You will notice that wire spring on right side of the frame (looking from back of the
frame into inside of the frame) is moving up and down. This piece of wire retains
both slide stop/releases in place as well as is forcing them down to neutral position.
To prevent unwanted slide stop activation (in my believe, due to recoil action) force
applied by spring wire must be increased.
My solution was to gently (with needle file) make existing grove going down forward.
In another words now only rear part of the grove have contact with spring. After it
was done both stop/releases levers are sitting stiffer in neutral position (slide stop is
down hard on frame). To remove slide stop/relies out for cleaning I do need to press it onto
hard surface (fingers are to soft), and I like it this way.

Hope my English is English enough.

[railroader]

It could be the slide stop is getting nudged by the rounds coming up or the slide stop spring is weak. You say your cz 75 works fine, try the slide stop out of it in your 85, if it works ok then the rounds in the mag are probably contacting the 85 stop. As for the slide stop spring if you take it out and bend the rear of the spring at the "knee" portion down a bit it will have more tension when you put it back in the gun. I have a CZ clone that was locking the slide back a couple times per mag and this fixed the problem. Mark

[PCRCCW]

My theory is either:
1- I need a new recoil spring.
2- I may be very very slightly touching the lefty slide release with my thumb (I shoot lefty).

Id say your answer is behind door # 1. Get a Wolff recoil spring, 14-16-18 pound weight and yould do well to replace the mag springs as well. They work in harmony togethor, if you go heavier recoil springs Id do the same for the mag springs as well.

95% of the time this happens, I replace the recoil spring and it will run perfectly again. Thats until my mag springs start to show their weakness...

Shoot well

[erem]

Check the magazine followers. I had a lot of problems with my CZ-75 locking back occaisionally. After replacing the recoil springs, the mag springs, having the slide stop cut back a bit, and having the feed ramp and breech face polished, I noticed that it only locked back on one magazine, which had a differently shaped follower than the others.
If you're using the same mags for the 75 and the 85, it's probably not that though....

-erem

[Walt Sherrill]

Lots of ideas above -- probably enough to make it confusing.

1) I don't think its mags springs or a bad follower: bad mag springs might keep a slide from locking back when the last round was fired, but they're unlikely to cause premature lock back -- since the follower is way down the tube when the problem is happening. (Its possible, however, that I'm overlooking something very obvious when I disagree...)

(Later thoughts on 1) If the mag spring is weak, it might allow the rounds to move around a bit, rather than pressing them tightly against the mag lips, thereby nudging the slide stop. That could be a possibility -- and might explain PCRCCW's finding it a successful fix.)

2) Ditto bad follower -- unless the follower has a very funny shape that causes the round to be moved to the left as it comes up the tube. Lockback on the next to last round or last round might happen with such a bad follower -- but not on the fifth or sixth round. If the lockback is happening early, look for another solution; if its happening late, you might have something.

3) Check the spring that holds the slide stop steady. If its loose, the slide stop can move around during recoil. If the slide stop moves too easily, you can bend the spring to make it tighter. (This was mentioned in one of the earlier messages. Or, get a replacement part from CZ.) If you have access to other 75Bs, 85Bs or an 85 Combat, its easy to compare spring tension.

4) Next, take the slide off, reinsert the slide stop, and insert a loaded mag, and see if the bullet tip nudges the slide stop. Slide a round off, and watch what happens when the next one comes up the tube.

If the rounds are bumping the slide stop, there can be several causes: a slide stop that is out of spec (remedied by taking a little metal off), an out-of-spec magazine that lets the top round wander to the left, against the slide stop, or out of spec ammo. (I don't think out-of-spec ammo is a candidate here, but its worth considering -- check OAL.)

And, of course, as previously mentioned, a strange follower -- but this would be causing problems only with the last round or two; not earlier.

5) When I first encountered this premature lockback problem -- on a new 85 Combat right after I bought it -- my gunsmith took a little metal off the slide stop where it was being nudged by bullets as they came up the mag tube. It hasn't had a problem, since. (And that's probably 8,000+ rounds.)

Good luck. Its a subtle problem.

[agony]

Thanks for all of the suggestions, fellas.

I'll update this post when I figure out the problem exactly.

Mr. Sherrill, you wouldn't happen to have a pic of the area that needs filed on the slide stop?

[Walt Sherrill]

No pictures, sorry.

But I'll bet your problem is the slide stop spring, not the slide stop.

As I suggested, however, pull the slide off, insert the slide stop, then put in a loaded mag. You'll see where the slide stop and mag/cartridges might interact -- and see if there's something that needs to be adjusted. If that is the problem -- you'll only want to take off as little as is needed to make the interaction stop.

Also -- see my later amendment to the response above, in italics. Weak mag springs, perhaps, should be considered as a possibility, as PCRCCW first suggested. (That doesn't explain the problem if you're using new mags, but certainly could be a contributor with older mags.)

[44rem]

Hi agony,
Friend pointed out that I'd not specified which grove to fail. I see it now, bugger.
Please allow me to correct.
When you will play with slide stop inserted without slide, you will notice that
left lever (the one with the catch for magazine follower) will move down a little from
neutral position to dead stop on frame and slightly move up when released (ignore
movements of the right one). This movement is not serving any purpose and may be
eliminated. What you are looking for is retain slide stop more firmly only !!!! in the
neutral position!!, without affecting other functions!!!!
When you strip both levers from frame, put them together on the flat, you will notice
grove cut on both (on the pin end socked) lining up into one grove. This is the grove I
was talking about.
With levers flat you may gently fail (make grove deeper) at the front halve ("front" as
the pistol goes), about < 5 DEG down forward will be perfect (be sure not to cut any
deeper onto rear end of the grove). Above modification will result in spring (wire
spring) acting ,mostly or only, onto rear half of the pin and socked of the both levers
assembly.
When completed, slide stop will rest down onto frame more firmly without going up
when lever released and move up only when forced by follower
Other member suggested bending spring (for more tension ?). From my experience it
will not do the trick.
Even if you will manage to reinstall over bend spring, the chances are that
spring will bend to previous shape during installation, !!!!! and most important with to
strong spring !!!!! slide may not hold open after you remove empty magazine, without
support of the follower stronger spring will move slide stop down and slide will shut
on empty chamber (trigger click, click, click, what the ??%$#* /I have been there
personally/)
One more thing, have look into hole (on the frame) for right lever socked, you will
see that spring moved down about 1/3 of the hole DIA, it is what is needed for the
slide stop spring to apply its force.
About reducing length of follower catch, in fact I had to add “length” to the catch for
the slide stop to work properly with followers on magazines for CZ 75 CADET .22
conversion kit and longer catch does not interfere with 9 MM followers. Slide stop
works properly in both configurations (as 9MM and .22RF)
Soon my Government will “buy back” my pistol and .22 conversion kit and crush it in
my view (if I wish to watch). Filing as same as at the family member funeral come to
me. I’m glad for you people, you still got yours.

Hope this time there is more “English” in my English.
Thanks, Chez.

[agony]

Again thanks to Walt, 44rem et al for the insightful info.

First of I checked out the spring tension that holds the slide stop. I compared it to my CZ75b. The CZ85 has good tension without any undue play...it is quite similar, if not 'tighter' than the 75B. So I don't think that's the problem.

I took of the slides and installed the stop pin in both frames. I loaded up the mags that came with the 85 and a couple of 75 mags that I know run reliably in the 75. I used different bullet types from HydroShoks to 124gr Flatpoints to different types of 115gr FMJ with different OALs. I tried mags loaded with different amounts of ammo and in different combos.

Here's my diagnosis:

1. The mag-to-frame fit is different between the 75 and the 85. It is sloppy with side to side play and front to back play with all the mags, but when locked in with the mag catch, the 75 seems tighter. The 85 still wiggles. The mag catches and springs on both appear quite strong. I think it has something to do with the fact that I removed the flat mag retention spring from the 75, and it still remains in the 85. Could it be that this flat spring that covers the mainspring may be causing undue rear-to-front pressure on the mag???

2. The slide stop lever is definitely out of spec on the 85. I was able to activate the slide stop on the 85 with most of my ammo...seemed to be worse with one of the 15-round factory mags that came with the 85. The only way I could replicate this in the 75 was by nudging a couple of the rounds forward a wee bit, but it still didn't catch the slide stop like it did on the 85. I took a caliper to both 75 and 85 slide stops, and noticed that the catch that activates the slide stop is set back nearly .1" compared to the 75 slide stop. This would, of course be enough margin to lock the slide back simply by the bullet nose during chambering of a round.

3. I took off a bit of metal from the 85's slide stop catch with a file, and sanded it smooth. An hour later, I finally was unable to activate the stop with loaded mags....for the most part. Here is where the mag-to-well sloppiness may come into play. Again, I wonder if the magazine retention spring has a negative effect on this.

What do you CZ experts think about this diagnosis? I truly believe it is multi-factorial.

I'll do a formal live fire test run this weekend to see results. I am going to try different ammo, all my mags including my old reliables that have ran well in my 75. I'll even try the 85 with the mag retention flat spring on and off the pistol.

Keep your fingers crossed for me...
:)

[44rem]

Hi Chokey,
Now I do known more about your gun.
I hope that you have got instruction/manual with one of yours guns.
Referring to magazine play, there is two ways to fix it. First “kitchen bench” way is to glue strips of plastic to inside and forward edge of the grip panels.
Second way involve more work, but final effect is not affected by the way you hold/squeeze handgun grip. Ideally, when magazine would rest its upper back portion onto block with ejector pin (part #10) , there will be no chance for projectile to catch on slide stop (to late, you already shorten it) . Flat spring #24 is pushing magazine forward, you do not need it (remove it). Insert magazine and check for back to forward play, if there is a play you may eliminate it with magazine catch #32, try pushing it deeper in (finger will be OK), if it stooped and magazine is firm - less work to be done, if magazine is “sloppy” - more work for you ( you may have to think again about first option).
Way to increase movement of #32 to engage and hold back magazine is to modify spring #33. Undo screw # 35 and remove magazine catch spring #33, remove magazine catch #32, on front of it (#32) you will notice two groves (narrow one on the left and wider one on the right). Narrow grove and left prong of spring #33 control force applied by magazine catch #32 onto magazine and prevent magazine catch #32 over travel (that is what stop you from pushing magazine catch #32 dipper in). Right prong in wide grove is to provide strength for left prong and prevent rattling of #32 without magazine in the place. But before you attempt any spring work, check the width of the left/narrow grove, if it is about 2X times bigger than prong itself you have plenty and enough room to work, if not, you need to enlarge groove (left one) by taking off metal from right side of the groove only !!!! do not make web between grooves thinner than
0.040” !!!!.
Now you are ready to do bending; magazine catch spring #33
- left prong, bend tip (about 0.100” of its length) to the left side to about 3 DEG.
- right prong, bend tip (about 0.200”of its length ) also to the left, and only halve of the left prong angle. Do not bend to much right prong as this will result in magazine catch become sloppy/rattling without magazine in the frame.
Please note; above modification will require many trails and screw #35 have tendency to spin spring #33, please make sure that both prongs are equally spread apart in the frame, each time you tighten it.
Be patient and your gun will work correctly with magazines regardless of their brand. Keep us informed.
Hope it may help you or some body else.
Thanks, Chez.

[agony]

Cool, I'll look into that after I give it a test shoot. Thanks, 44rem!

[agony]

Well, after working on removing some metal from the slide lock area, I took it to the range today.

I still had problems! :barf:

The slide still locked back at least once every 15 rounds.

I'm ordering a new mainspring, some new extra power mag springs, and may order a new CZ85 slide stop.

If that doesn't work, then I'm selling it.

[Walt Sherrill]

I can appreciate your frustration.

You have two other options: 1) contact Mike Eagleshield at CZ-USA for advice or parts. (He's the CZ gunsmith, and can be reached through the CZ-USA website.) CZ might do the repair for a minimal fee. 2) Let a local gunsmith look at it. Option 2 is likely to be about the same cost as 1, since shipping guns by FedEx or UPS is not cheap -- but its likely to be quicker.

I had the same problem with my CZ-85 Combat when I first got it. My local gunsmith did the repair quickly and cheaply. It took him a few days to get to it. (That's where I first learned of the "slide stop" solution.)

The Transitional 85s are relatively rare here in the US. Not collectors guns, per se, but sought after. (What you have is, in effect, a CZ-85 Combat; only the sights are different.)

Don't sell it quickly or cheaply. (You might consider putting it in the CZ-FORUM's classified section if you get so frustrated that you want to get rid of it.)

I might be able to offer you something you'd like in trade, too. (You can contact by PM, below.)

[PCRCCW]

Walt,
Always offering good advice. Mike is very good...he's the only CZ authorized Fix it guy in the states...and given that he's quite reasonable.
Walt would give your gun a good home if you should decide to let it go.
Shoot well....hope you get her figured out.......:D

[agony]

Well, I removed some metal and the first update, I still had PLB (Premature Lockback...can we patent this acronym? :) )

I ordered new extra-power springs for all of my 15 round factory mags, and an extra power recoil spring. Then I did a little gouging of the recess where the return spring for the slide release sits, as mentioned by 44rem. And to top it off, I swapped the spring from the reliable CZ75b with the 85.

Took it to the range....still the same problems.

Then I did a 'tempering' job to the slide stop spring after reshaping it. (This was a good suggestion by a fellow member at a different forum, who had the same prob with a CZ75b, and this is how his 'smith did it). This was done by a local smith/guru.

Took it to the range. The problem seemed to get worse (especially since I changed to the extra power springs).

Took it to the guru, who suggested I take more metal from the slide stop. So now I'm back to square one. I'll take off some more metal to the point of absolute minimum tolerences for proper function, and try again!

[Walt Sherrill]

If you think the problem is too much front to back or side to side movement of the mag in the grip, you could find out pretty quickly by putting strips of electrician's tape on the mags. (Try one layer, then two...)

If that solves the problem, then you know where to build up the inside of the grip frame with plastic or a slim piece of steel (and superglue or epoxy.)

I suspect the tape needs to be applied to the front of the mags. If they're shifting forward, they could allow the nose of the bullets to nudge the slide stop.

You may have explained this earlier -- but I missed it when I reread the message chain... Are the mags fully to spec? (Do they work right in your 75B? It may just be you've got some after-market mags that aren't worth a crap.)

[erem]

Yeah, I'm still having the same problem. I'm not sure how I managed to convince myself that the mag followers were the problem :uhoh: but reading Walt's post made me realize that was incorrect.

In order to solve mine, I have tried the following:

1. Had the feed ramp and breech face polished
2. Had the slide stop cut back (twice so far)
3. Replaced the recoil spring with a 16# wolff
4. Replaced the mag springs (i've got one each at +5%, +10%, and +15%. none work)

and it still locks back, once every 100 rounds.

I'll have my smith take a look at the slide stop spring, and maybe cut the slide stop back again tomorrow.

[Walt Sherrill]

I have a 75B Compact that I bought from a forum member.

It would consistently lock back prematurely with the one factory mag that came with it. Always at the sixth round. I couldn't (and still can't) for the life of me figure out what the problem was. It couldn't be the follower, I don't think it was the springs -- nearly new -- and the ammo was OK. I really need to get myself a micrometer.

Replacing the factory mag with a set of Pro-Mags solved the problem.

(I never bothered to take the mag apart to look for burrs, etc. I'll do that next. But I didn't see any way that a burr or problem would make it lock back...)

Happily, the factory "Compact" mags have the same mag body as the full-size factory mags, with a different base; I can put my "Compact" base on a known good mag and see if that solves the problem.

[agony]

Mr. Sherrill,

Yes I have used 5 different mags. All spec factory step-based 15 rounders, 4 of them have been flawless with the CZ75. The factory 15 rounder that came with the 85 functions flawlessly in the 75. And the 75 doesn't even have the flat mag retaining spring, as I took it out years ago. When I took apart the mags to replace with higher power Wolff springs, the followers were all exactly the same. I'll try the duct tape thing.

Maybe if I remove the CZ85 mag retaining flat spring? Hmmm...............

[railroader]

I didn't notice in your post but did you ever swap slide stops with your 75b and your 85 combat then take them both to the range to see what happens? Just curious. Mark

[agony]

The 75 slide stop doesn't fit my CZ85.
:(

[Walt Sherrill]

The 85 is an ambidextrous slide stop, so it doesn't work in the 75B.

(There is a special fitting in the frame on the 85, and the far end of the slide stop of the 85 fits into that fitting, which is a lever.)

Agony: Not duct tape -- Electrician's tape. Its thinner.

[Esky]

44rem said,Soon my Government will “buy back” my pistol and .22 conversion kit and crush it in my view (if I wish to watch). Filing as same as at the family member funeral come to me. I’m glad for you people, you still got yours.


You have my sincere condolences, 44rem. I finally left Australia, after 30 years in Western Australia, and a big part of my decision to return to the USA was the irrational firearms laws in Oz that are causing you such pain.

Even here in Kalifornia things are better than in Australia, though the antigunners are hard at work trying to make us all defenceless. <sigh> You'd think that the rising crime rate would give them a clue, but no.

Thanks for the advice on the slidelock problem! I just bought a new CZ 75b Tactical, and hope that I don't have this problem, but I've filed this forum away in case I need the help...

Esky

who does not know if he'd have the strength to watch the destruction