Cracked Slide?

[Tandem938]

  Slide on CZ75 Compact .40 S&W seemed to seize during a range session.  Inspection found cracks along where the return spring “pocket” meets the main slide.  Sent to CZ-USA.

  Anyone else seen this?  A few thousand rounds through a 2011 model, but not “high mileage”.



Sent from my iPhone using Tapatalk

[SI VIS PACEM PARRABELLUM]

Nope never seen that before. Doesn't mean it hasn't happened though.  See what CZ says about it.

[Tandem938]

Sent back to CZ-USA.  Sounds like they are inclined to replace slide - if they can find one.  May convert from .40 to 9mm, which would be fine with me.  Interested in whether they have insight on the cause.


Sent from my iPhone using Tapatalk

[George16]

What ammo and recoil spring were you using?

[Mercs]

Did you notice excessive recoil prior to the event? Looks like it was either undersprung or had a defect in the casting


Sent from my iPhone using Tapatalk

[Tandem938]

  I was shooting American Eagle 180gr FMJ.  Spring was Wolff, but standard weight (17#), I think.  No discrete event, but I had a couple of random FTF’s and it seemed like it wasn’t returning to battery smoothly.  I think the crack widened and the pocket for the spring started to rub the frame, as it tipped down because of the crack - it essentially seized, but it was not the slide rail , but contact underneath with the frame.

  Historically, it had had some FTF issues, but was reliable since I had it Cajunized a couple of years ago (Defensive Carry Package & general tuning).

  Thanks for asking and any insights are welcomed!

[SI VIS PACEM PARRABELLUM]

I'd agree with the cause being a spring issue but it has been noted the .40 can beat some guns up prematurely as well.

[M1A4ME]

Looks like the slide was making contact with the frame.  The contact stopped rearward movement, not the combination of cocking the hammer, compressing the recoil spring, etc.  I don't see any finish wear/damage like that on my 9MM Compacts.

I wonder if the slide was just a bit too long right there at the back of the spring pocket.

I guess the other side of that is if the spring compresses completely and the coils pound each other on every shot - how long will the recoil spring last??

Shame to "lose" a fairly rare pistol (if it has to be converted to 9MM).

If CZ can't get you a .40 slide I think you should ask them for 9MM magazines, too.  It's not just the slide/barrel that has to change, you'll need 9MM magazines, too.

[badwrench]

Did you notice excessive recoil prior to the event? Looks like it was either undersprung or had a defect in the casting


Sent from my iPhone using Tapatalk

If I remember correctly, the slides aren’t cast..they’re machined from bar stock. The frames however, are cast..

[Tandem938]

Shame to "lose" a fairly rare pistol (if it has to be converted to 9MM).

If CZ can't get you a .40 slide I think you should ask them for 9MM magazines, too.  It's not just the slide/barrel that has to change, you'll need 9MM magazines, too.

 
  I agree with “shame to lose”, but the .40 Compact seems to have had more than its share of problems.  I can be happy either way.  I agree on the magazine thought and sent two with the gun - as a hint, if a caliber change was the possible result.


Sent from my iPhone using Tapatalk

[Indy_Tim]

Sent back to CZ-USA.  Sounds like they are inclined to replace slide - if they can find one.  May convert from .40 to 9mm, which would be fine with me.  Interested in whether they have insight on the cause.


Sent from my iPhone using Tapatalk

I have a spare slide for a .40 75B Compact if you are interested.  I think the early .40 Compacts were not CZs best work and when you look at some of the things that they did to make it work, it shows.  In my opinion, the slides were too light at 289 grams which is what they used on the 9mms.  Later CZs in .40 had a 340 gram slide.  To compensate for the increased energy, the cut the spring housing at the front of the slide short to give the slide a bit more travel.  The downside here is that there is not enough room to run a heavy recoil spring without getting spring bind and if you run too light a recoil spring, you get frame impact.  You need to run that slide with as heavy a recoil spring as possible and a heavier main spring to control recoil.

I put a 40P slide on my 75B compact and it’s now a really nice shooter.  The heavy frame and heavier slide put the gun at almost SP01 weight but in compact form.  The 40P slide is more accurate to boot.

[Indy_Tim]

...
I guess the other side of that is if the spring compresses completely and the coils pound each other on every shot - how long will the recoil spring last??

My experience was about 100 to 150 rounds per spring.  I had also tried the DPM Recoil Reduction system and ordered one for the P06.  That lasted 10 rounds before it was destroyed.  That’s when I found out about the short spring house.  DPM was very good though and send a custom configured one for no charge along with a replacement for the original.  The custom one lasted about 100 rounds but the replacement original is running in my 9mm compact still.

[Tandem938]

Thanks for the offer, Indy_Tim!  I might be taking you up on that.  CZ-USA has the gun and I expect a response in a couple of weeks.  If they can’t come up with a .40 slide, I’ll be coming back to you to discuss price. 

Is the 40P slide the same size, only heavier?  Sounds like a good long term solution.

[Indy_Tim]

Thanks for the offer, Indy_Tim!  I might be taking you up on that.  CZ-USA has the gun and I expect a response in a couple of weeks.  If they can’t come up with a .40 slide, I’ll be coming back to you to discuss price. 

Is the 40P slide the same size, only heavier?  Sounds like a good long term solution.

The 40P slide was a drop in fit for the .40 compact with one minor alteration.  To run on the standard safety frame, you need to have a small notch cut to allow the safety to actuate.  It’s a small enough cut that my machinist didn’t even charge me to doing it.  Without that notch, you can run the gun just fine but cannot engage the safety.

[Indy_Tim]

The biggest downside to the 40P swap is that you now have the funky 40P sight issue to deal with if you want to replace them.