What might cause this?

[Dan-O-Mite70]

I recently put in a new 15 lbs. recoil spring in my Tactical Sport.  I also have a Springco recoil reducer which has been in for quite some time now.  It is a .40 cal.  Upon a recent, and regular cleaning, I noticed a crack in the front of the lug (I think that's what it's called) on the barrel.

I'm wondering if the new spring could have anything to do with this, or was it just time for this to happen?  I have had this gun for about 2 1/2 years now, and it has about 25,000 rounds through it.  I do shoot IPSC Major loads.

This gun has been functioning perfectly.  Even with this crack I didn't notice anything wrong until inspecting while cleaning.

Can you see any reason for the spring to be the cause of this?  Any other ideas what would cause this?

I have included a picture, I hope I did it correctly.

[Cesar]

If it wasn't a defect in the barrel itself, it looks as if the crack developed due to hard hitting on slidestop during rearward movement. Did you break slidestop/s before? Using a lot of +P ammo and reduced power recoil spring?

[CZ75BRocks]

+2 Cesar

[Dan-O-Mite70]

I have not broken any slide stops, but I do shoot Major power factor in IPSC.  I'm not sure how that relates to +P loads.  My Power Factor is usually around 176 - 179.  PF = bullet mass x velocity.  I shoot 180 grain bullets.  Velocity is usually 970-990 ft per second.

[Walkure]

I have not broken any slide stops, but I do shoot Major power factor in IPSC.  I'm not sure how that relates to +P loads.  My Power Factor is usually around 176 - 179.  PF = bullet mass x velocity.  I shoot 180 grain bullets.  Velocity is usually 970-990 ft per second.

Factory 180gr loads yield about the same PF out of my TS. I chrono'ed at 177PF shooting factory Federal 180gr FMJ at my last major match (Ohio sectional back in October).

I also run a lighter recoil spring - 13#. No issues whatsoever for me, but I'm not even at the 10k mark yet (just got it summer '09).

With a crack there, I would think the type of force it suggests would have started cracking slide stops before the barrel. So perhaps there was a microscopic defect there to begin with. I haven't heard particularly good things about the Sprinco reducers in CZs, BTW...

[Cesar]

I know what PF is as I shoot USPSA and IDPA.
Either way, if I were you I'd start looking into getting a replacement barrel just to be safe.

[Dan-O-Mite70]

 I haven't heard particularly good things about the Sprinco reducers in CZs, BTW...

Can you be more specific?  I haven't had any problems with mine, and in theory I would think that it's good to have the extra spring force at the end of the slide movement, a little extra cushion between the slide and frame.

[Dan-O-Mite70]

I know what PF is as I shoot USPSA and IDPA.
Either way, if I were you I'd start looking into getting a replacement barrel just to be safe.

I haven't shot it since I found out, and I won't until I get a new barrel.  Right now the frame and slide seem fine, I wouldn't risk damaging them as well.

[Cesar]

Also, to make Major you need only PF165+, not much over 165..
I shoot Minor 9mm and load my rounds with PF129 just so that I can knock metal plates off at all distances

[Dan-O-Mite70]

Major power factor in Standard division in IPSC is 170.  Maybe your thinking of another shooting sport.

[Cesar]

Sorry, I was thinking USPSA.

[Walkure]

 I haven't heard particularly good things about the Sprinco reducers in CZs, BTW...

Can you be more specific?  I haven't had any problems with mine, and in theory I would think that it's good to have the extra spring force at the end of the slide movement, a little extra cushion between the slide and frame.

General reliability issues. I'm trying to think... there may have been some talk of durability issues as well, but I don't recall specifics. All I know for sure is that yours is the first time I recall ever reading a positive experience with those reducers in a CZ platform.

[Dan-O-Mite70]

Well I just heard from the factory.  Because I was using aftermarket parts in the gun (the Springco recoil reducer), they will not cover it 100%.  They will however, go a long way and give me a replacement barrel.  I think this is very good of them, and happily agreed to the offer.  However, I was told that it would need to be fitted to my slide by a gunsmith. 

Can someone tell me what would need fitting, I thought it would just drop in.

[Dan-O-Mite70]

Has anyone had to replace a barrel?  Which areas would need to be looked at?

[phoenix79]

The locking lugs on top will need to be fitted to your slide i believe