CZ-85 Slide Lock Problem

[Blind Bat]

I picked up a used CZ-85B circa 1994. The gun shoots fantastic but I was having a lot of FTF's with the hi-cap mag that came with the gun. I recently purchased a Mec Gar mag from Brownells which has solved my FTF problem but now I noticed that the slide likes to lock back before the last round. This afternoon I had it lock back three times on one mag! I was only using the new Mec-Gar mag.

I'm a lefty and I tried to make sure my thumbs weren't hitting the slide lock on the right side of the pistol. I know CZ's have issues breaking slide locks but I've never heard of one that engaged too early. Do you guys think it's me/my thumbs or the gun? Slide lock spring, maybe?

 

[RDak]

I really don't know Blind Bat. I've never had that problem with my CZ's. Maybe give CZ-USA a call.

http://www.cz-usa.com/about_contacts.php

 

[Blue .45]

My '07 CZ75B had this problem. A new slide stop spring cured the problem for my gun. However, this might not necessarily work for you.

If you try the CZ forum, you can see what others have done to fix this problem.

http://czechpistols82792.yuku.com/bczechpistols82792


You find some useful tips in this thread.

http://czechpistols82792.yuku.com/topic/3411/t/Premature-Lockback-of-Slide.html

BTW, CZ USA sent me a new slide stop and spring, no charge. They have very good CS.

 

[Cliff47]

The CZ Forum has a new address www.czforunsite.info. Lots of good information.

 

[ExtremeSquared]

remove the slide and take pictures looking into the frame with both empty and loaded mec gar inserted

 

[railroader]

You can also add tension to the slide stop spring by bending it a little at the "knee" of the spring. I had to do that to a cz clone that did the same thing. Mark

 

[Gary G23]

They have changed the design of the slide stop spring. A new spring should cure the problem. It did for me.

 

[Blind Bat]

Thanks Guys! I tried playing with the slide lock spring and if anything I made it worse. I'll give CZ-USA a call tomorrow and order another spring. It's also a good excuse to order a 15lb hammer spring and a flat mag brake.

ExtremeSquad - I took a look at the mag follower with the slide removed. It's definitely not hitting putting any pressure on the slide stop with one round in the mag.

I'll post again after the parts come in.

 

[Blind Bat]

Follow up -

It took me a while to get through to CZ. The first time I called their phone system was having issues, the second time it went to voice mail and no one called me back (or if they did they didn't leave a message) but the third time I got through to someone right away. I ordered the slide stop spring, a new recoil spring and 15lb hammer spring. I asked about a flat mag brake but the parts guy said they just bend them flat when people request drop free mags.
$19 shipped and it arrived in three days. I can't complain about that!


I've fired about 100-150 rounds since installing the springs and the slide has only once locked back prematurely. That might have been caused by my thumb placement. Previously it was locking back aprox. every fifth round.

I also took the time to detail strip the pistol and polish the trigger bar, ejector and sear surfaces as per these instructions. The result has been a very consistent 4.5lb trigger in SA mode and a much nicer 8-9lb DA pull. The SA feel is smoother but it's hard to say if that is a result of the polishing or removing years of dirt and grit that built up under the extractor assembly.

My only minor gripe is that the SA break isn't completely clean. When I start pulling the trigger there is a slight staging effect. The hammer will move back a bit then I need to apply about another pound of pressure for the sear to move that last little bit and to drop the hammer. As a rule, I never touch the hammer/sear hooks since I don't have the proper stones, files, jigs and skills. However, I might need to do some research and buy some tools because once that little bit of staging is gone the trigger would be perfect. I like a 4-4.5lb trigger pull and I like the look of the stock hammer better than the comp hammer.

 

[burningsquirrels]

if you poke around the CZ Forum there's info on how to modify positive engagement from the sear angle AT YOUR OWN RISK. i did this to create perfect neutral engagement, and the hammer drops creep free.

http://czechpistols82792.yuku.com/topic/14688/t/CZ-75-Trigger-job-lots-of-pics.html

i highly recommend installing the CZ competition hammer first. the comp hammer has a hook so short, you may not need to modify the sear angle at all. combined with the 15 pound mainspring, it will make for a very nice trigger pull. i believe that most everyone with a match-like trigger uses the 15# mainspring and comp hammer... but as always, YMMV.

 

[Blind Bat]

squirrels - I actually used that page as a guide for doing the detail strip. Since I didn't have stones or really small fine files I didn't touch the sear or trigger hook surfaces. I'm also skeptical of changing the angle of on the sear for fear of removing the surface hardness.

The next time I have the pistol apart I'll try to smooth the hammer hook just enough to remove any burrs or ridges.