Resolved - Original: Need help. Can't get P10S to run the way it should

[czgen]

I have had my P10S for quite a while now. Purchased it locally second hand. I love the gun, except I can't get it to run well.
Here is my history with this gun:
Purchased used with very low round count.
Right from the first several hundred rounds I had some issues with the slide not locking back after the last round. I ran a couple of boxes of ammo loading just one round in the magazine to diagnose the issue and also shot one handed. In many cases I was riding the slide stop (as I'm more used to the 1911/CZ75 platform). I adjusted the grip, but on some occasions I noticed that my hand was not near the stop lever and it still didn't lock back. On one occasion I had an issue that the gun locked back with rounds still in the mag. I thought that I probably kicked the slide stop up with my thumb during the recoil.
Several hundred rounds in, I decided to cut off the left lever completely. I slingshot the slide to release and still have the lever on the other side to clear the malfunctions, so I felt that I have nothing to lose.
Things got weirder.
Every hundred rounds I get a couple of failures when the slide will lock back with rounds still in the mag. There is no lever to kick up during the recoil. I'm clueless. At the same time I noticed that on some occasions the slide still won't lock back on an empty mag. Now I can't blame myself for riding the slide release. I notice that the issue happens more often during slow fire when I loosen the grip a bit. I don't think I ever experienced an issue during fast fire. I got DMPS RSA and tried different recoil springs that came in the kit. I still have issues.
Now I'm lost. I understand that the issue may be due to limp-wristing, though I can't reproduce the issue more consistently even when just shooting with a weak hand. In either case I won't trust a gun that I can fail with limp-wristing. I tried different mags. I got another slide stop spring from CGW. Didn't help. I adjusted the spring a bit to increase the pressure. Still get these weird issues when the slide just locks back with rounds in the mag and sometimes doesn't lock back. I don't really know what else could be the issue. I can't send the gun in to CZ, because I'm not the original owner and the gun was already taken apart/modified. I hope that someone can suggest a solution.
If I can't find a solution, I will probably just file down a bit the tab on the slide release that catches the slide and increase the pressure on the spring so the slide will never lock back, unless I manually push up the lever all the way. That way I won't ever get a lockback on the last round, but at least I will trust the gun to reliably run the full mag. I hope there is another way.

[Grendel]

Check that the ammo you are using is not nudging the slide catch up when it's in the magazine. If it's loaded long it can push the catch up, especially under recoil. Sometimes a small bevel is needed to be filed on the catch to prevent this, or switching to a shorter OAL ammunition.

[czgen]

Thanks a lot. I ruled out the ammo, because I used several different boxes of ball and SD ammo and had the same issue. I can't believe I didn't check it closer after battling with the issue for so long. I checked the slide catch inside and found some marks from brass. With slide off I took a loaded magazine and pushed it in. Sure enough the back of the brass scraped the catch and pushed it up. Now I need to disassemble the gun again, file, polish and test. I'm pretty sure that the issue will go away. Once that is fixed I will adjust the spring to reliably lock the slide back. Man I love my P10S, but this thing was driving me crazy. I should've come here earlier

[czgen]

Just wanted to follow up. I'm pretty sure that I got the issue resolved now. I have to say that this gun from the beginning was not the best example of CZ manufacturing. It was built very sloppy, rattled worse than a Glock, trigger was gritty and not that great. Still I just loved how it felt in my hand and was happy to find the optic ready variant locally at a good price. Trigger got better with use and now is pretty awesome. The gun still rattles like crazy, but it is very accurate, so I learned to dismiss it.

The issue with the slide catch/release on the other hand is really something. The tolerances on this build just got it messed up bad. The rear of the cartridge in the mag was pushing the slide catch up when mag was inserted. After that the catch was not going all the way down, if mag was at a certain angle and the catch was resting on the back of the magazine. So even a fairly light bump could cause the catch to jump up and hold the slide back with rounds still in the mag. Also at some angles the catch will go a bit lower, but would be pinched by the back of the mag, so it won't go up and won't hold the slide back when mag was empty. Once I finally saw this, I had to put a huge taper on the catch to make sure that it does not contact the brass or the back of the magazine. After the fix, I didn't get any issues so far. It will take several hundreds more trouble free rounds before I can fully trust it but I'm sure that it will get there.

This gun really should've went back to CZ for a replacement, but I was not the original owner (stupid rule) and already disassembled the gun before noticing the problem, so warranty repair was unfortunately not an option. I'm glad that I was able to find the problem with the help of Grendel and this forum. I hope that my experience will help someone else.

[Psyop96]

Just curious whether this one is a Uhersky Brod or CZ-USA build? If the latter, it will obviously not have “Made in Czech Republic” nor matching SN’s on the slide and barrel.

Edit…just wanted to add that my KC built P-10S has been superb. Hope CZ-USA makes it right for you.




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[czgen]

Just curious whether this one is a Uhersky Brod or CZ-USA build? If the latter, it will obviously not have “Made in Czech Republic” nor matching SN’s on the slide and barrel.


Sent from my iPad using Tapatalk

It is a CZ-USA (Kansas) built. I believe finding an optic ready P10S made in Chech Republic that is for sale in USA is close to impossible. As a matter of fact, I wanted to buy another brand new P10S OR locally to hopefully find a good one, and I just couldn't. I don't think I will be getting one now. I love my P10S, but it's difficult to recommend to a friend after the issues with mine and no stock to check locally. 

[bonj]

I wonder if CZ would repair it being not under warranty and with a cost to repair. After all they are the experts. It might be worth it, if they do.

[Claymore504]

I would give CZ a call. I have a feeling they will take it back and look at it for sure. They are really good about just replacing with a new gun from what I have seen.

[czgen]

I sent CZ warranty dept a message explaining everything. Will see what they have to say about it.

Below are couple of pictures showing the issue and what I had to do to correct it.

[czgen]

Found another picture before I filed/beveled and polished the slide catch. You can see how brass left the mark in the center and magazine left the marks on the sides. I still can't believe I didn't see it earlier.

[armoredman]

Odd indeed - what did CZ say?

[czgen]

Odd indeed - what did CZ say?

It looks like CZ-USA will take care of this. They approved the warranty repair. Will ship it back to CZ in couple of days. Hopefully they can also tighten up the slide-to-frame fit a bit.

[czgen]

Wanted to post an update to close this out with a happy ending.

I received my P10S back from CZ over a month ago. They replaced slide stop, slide stop spring and front insert. I think front insert is what did the trick moving the slide stop a bit further back. I must say that the back of the casings still rubs against the slide stop and lift it up a bit when mag is inserted, but slide stop now goes down just fine and doesn't cause issues anymore. CZ also replaced the firing pin and auto safety due to wear.

Guys at CZ also polished the breech face lead in. I don't think I had any issues with it and didn't bother doing it myself, but I'm glad that they did. I will gladly take this small reliability upgrade.

After CZ replaced the front insert, the slide to frame feels just a bit tighter. Other than that they noted that the fitment is normal and won't cause issues. I totally agree with this assessment. Replacing the rear insert might make it just a bit tighter, but I won't bother with this.

Not everything was rosy after the return from CZ.
During my first dry firing session, I noticed that the new striker (replacement from CZ) got stuck in the breech face hole a couple of times. I doubt that it would've happened during live fire. Slight smoothing of the striker tip took care of this. I must say that I discovered a long ago that the hole in the breech face on my P10S is a bit undersized. When I tried to upgrade my striker with one from CGW while chasing the smoother trigger break, the CGW striker didn't fit inside the hole at all. No problems anymore with the stock striker.

After repair on the first trip to the range I noticed that slide locks back fine with my newer stock mag, but it often won't lock back with an older mag and won't lock back at all with a couple of mags that have +2/+3 extensions. Upon inspection I noticed that the new slide stop rubs a lot against the polymer frame, so the spring in the mags with extensions can't overcome this friction and lift up the slide high enough. Slightly bending in the sides of the slide stop helped a bit, but didn't make the movement completely smooth. I had to sand the sides of the polymer frame a bit to take care of this issue. Now the slide stop moves smoothly and there are no problems with lock back even with my older +3 mag.

Now after several trips to the range and several hundreds rounds I can say that the gun functions flawlessly with any stock and extended mag that I have. I think the whole initial issue with the slide stop was caused by manufacturing tolerances stacking the wrong way. The gun that I sent to CZ was functioning flawlessly after the modification that I did and described earlier, but the issue was that the slide stop didn't look stock at all after removal of a lot of metal to get it working. I still had to do some work after CZ replaced the parts on this gun, but I'm glad that it worked out in the end, because my P10S is my favorite carry and now I can carry it with the new stock slide stop that doesn't look heavily modified. I wish that I didn't have any issues from the beginning, so I could easily recommend a P10 to my friends. I hope it was just my luck of the draw. I'm very pleased that CZ was willing to take care of the issues and did so very fast. Maybe a bit more testing before sending it back would've caught the minor things.

[bonj]

sounds like a PITA resolve, I most certainly will never buy one. Thanks for your post!

[Raven45]

Sorry to hear you had to resolve so many problems, and glad CZ customer service took care of it for you.

I purchased a P10S several months ago and installed a HB trigger in it. 

It has run absolutely perfectly with zero malfunctions using five (5) different magazines

I have used nine (9) different styles/brands of ammo:
.  Four (4) brands of factory JHP ammo
.  Two (2) brands of factory FMJ ammo
.  One (1) handload with a JHP bullet
.  One (1) handload with a FMJ bullet
.  One (1) handload with a RN cast bullet

I would caution against deciding that this pistol is unworthy based on the experiences of one shooter with one pistol.  Especially considering the problems were corrected by the manufacturer, albeit a bit slowly.

But it is certainly a personal decision.