CZ Shadow hammer is dropping when out of battery

[Blackstone45]

Going through the IPSC equipment check manual, and one of the tests is the 'Disconnector' test. The hammer must not fall when the trigger is pulled when there is a 1.5mm gap between the slide and barrel (ideally the gun should not fire if it's even slightly out of battery). In the case of my SP-01 Shadow, the hammer is dropping even when there is a significant gap between the slide and barrel (ie. the slide is significantly retracted). What could be causing this?

[IHAVEGAS]

1 hour ago, Blackstone45 said:

a significant gap between the slide and barrel (ie. the slide is significantly retracted)

I have a Shadow 1 target from CZ custom and a Shadow 1 Orange, both guns are as delivered from the manufacturer/Custom shop. 

The hammer will drop on either gun with the slide back about 1/4" (6 or 7 mm), but at 1/4" of slide retraction the slide has not begun to move back away from the barrel and I suspect either would pass the 1.5mm gap test.

 

For what it is worth. Ideally someone will chime in who knows details of the gap test, I'm not an IPSC shooter.  

[rowdyb]

Stock hammer and disco?

[Blackstone45]

29 minutes ago, rowdyb said:

Stock hammer and disco?

Aftermarket hammer

 

After further research and testing, it seems it's related to the trigger bar and how it interacts with the sear/hammer? On my other Shadow, if I push down slightly on the trigger bar (like how a slide would), and then pull the trigger, the hammer won't fall.

Edited September 5, 2023 by Blackstone45

[shred]

I vaguely remember it's gap between barrel hood and breechface they look for, not slide travel or many guns would fail. @Schutzenmeister probably knows more.  I wasn't paying a great deal of attention to that test at the last half dozen IPSC equipment checks I've been through.

 

[IHAVEGAS]

13 hours ago, shred said:

I vaguely remember it's gap between barrel hood and breechface they look for

 

Something like that is what intuition would suggest, I don't know that I have ever owned a gun that would not drop the hammer with the slide back 1.5mm (0.0590") or less. 

[Blackstone45]

Sorry yes, it is a physical gap of at least 1.5mm between the breech face and barrel. Unfortunately mine is dropping the hammer with plenty of gap. It seems there's something up with the way the trigger bar is interacting with the disconnector.

[GeneBray]

Based on your posts the pistol clearly fails the IPSC safety test. That assume I read your post correctly.

 

If you did the replacement parts it’s going to be you who needs to fix it. Sounds like you already know the fix. Increase downward force on the trigger bar spring and then ensure that fixed the problem and didn’t create new ones. 

[Blackstone45]

10 minutes ago, GeneBray said:

Based on your posts the pistol clearly fails the IPSC safety test. That assume I read your post correctly.

 

If you did the replacement parts it’s going to be you who needs to fix it. Sounds like you already know the fix. Increase downward force on the trigger bar spring and then ensure that fixed the problem and didn’t create new ones. 

What role does the trigger bar spring play?

 

I've tried pushing down on the 'ears' of the trigger bar (like how the slide would) and the trigger will still drop the hammer. I'm assuming this means the end of the trigger bar that interfaces with the sear isn't being pushed down enough to disengage from the sear?

[HesedTech]

7 hours ago, Blackstone45 said:

What role does the trigger bar spring play?

It holds the trigger bar up so it can push the tab on the sear and lift it off the hammer. The bumps on top the trigger bar then ride the grooves on the slide pushing it down below the sear so it can reset.

 

The answer to your question is the slide and the trigger bar aren’t timed to prevent the drop. If you replaced the trigger and done “tuning work” on the trigger bar it’s likely there’s your problem. 

 

In DA the disconnector is the part which releases/drops the hammer prior to it fully engaging the sear. It, the disconnector rides up the frame until it comes off the trigger bar and releases/drops the hammer. 

 

Here’s a video of how it works.

 

 

[Blackstone45]

3 hours ago, HesedTech said:

It holds the trigger bar up so it can push the tab on the sear and lift it off the hammer. The bumps on top the trigger bar then ride the grooves on the slide pushing it down below the sear so it can reset.

 

The answer to your question is the slide and the trigger bar aren’t timed to prevent the drop. If you replaced the trigger and done “tuning work” on the trigger bar it’s likely there’s your problem. 

 

In DA the disconnector is the part which releases/drops the hammer prior to it fully engaging the sear. It, the disconnector rides up the frame until it comes off the trigger bar and releases/drops the hammer. 

 

Here’s a video of how it works.

 

 

I'm not sure if the issue is on the trigger end, or a timing issue between the slide and trigger bar. The slide is pushing the trigger bar down just fine, the problem is that despite the trigger bar being pushed down, it is still engaging and releasing the sear. My understanding is that if the trigger bar is pushed down, it should be clear of the sear.

[HesedTech]

5 hours ago, Blackstone45 said:

My understanding is that if the trigger bar is pushed down, it should be clear of the sear.

It isn't "clear of the sear", it clears the tab on the sear.

 

In DA the trigger bar is pushing the hammer back (that's why the pull weight is higher) until the disco releases the hammer, while in SA it hits the sear and releases the hammer. The hammer is back and hooked to the sear because the slide (or manually) set it. The sear spring is there to engage the sear into the hammer hooks.

 

If a cocked hammer set in the sear falls when the trigger is pulled and the slide is out of battery only one thing is happening, the trigger bar is pushing the sear up.

 

If your trigger, sear and hammer parts are modified or replaced, the solution is to go back to stock and make changes one by one until you find the what started the issue. 

 

The rule isn't really for safety purposes, it's to force competitors into a stock or near stock configuration. 

 

[Schutzenmeister]

On 9/5/2023 at 6:28 PM, shred said:

I vaguely remember it's gap between barrel hood and breechface they look for, not slide travel or many guns would fail. @Schutzenmeister probably knows more.  I wasn't paying a great deal of attention to that test at the last half dozen IPSC equipment checks I've been through.

 

 

1st - I didn't write these procedures ... I also am not usually the person actually performing the tests, especially so when I'm the RM.  However:

 

The measurement gap to which they are referring is the gap between the barrel hood and the breech face as @shred has indicated.  By this point in the cycling virtually ALL semi-automatic handguns SHOULD have activated the disconnector thus preventing the trigger from being able to release the hammer and ensuring it cannot again be released until the gun is fully (or nearly fully) back into battery.  Let's face it ... A gun that goes bang while not in battery is unsafe!  It also prevents a gun from going full auto, another unsafe situation.

 

And yes ... the slide on most semi autos I'm familiar with, certainly the ones we use in this sport, will travel some distance to the rear BEFORE the barrel disengages and presents you with a measurable gap.  (The differences may be some guns like the Browning Buckmark or the Walther PPK with a FIXED barrel.)

 

Where did they come up with the 1/16" (1.15875 mm) and 1.5 mm?  The gods only know ... and the oracles at Delphi have as yet to provide me with any insight on that topic!  FWIW - A US penny is listed as 1.52 mm thick.  (A dime is too thin ...)  Your other option for measurement is a set of automotive feeler gauges, for those of you old enough to remember setting the gaps on plugs and points!

[Schutzenmeister]

1 hour ago, HesedTech said:

 

The rule isn't really for safety purposes, it's to force competitors into a stock or near stock configuration. 

 

 

I cannot possibly disagree more.

[IHAVEGAS]

59 minutes ago, Schutzenmeister said:

I cannot possibly disagree more.

 

Are there any known incidents of people getting hurt due to a gun being out of specification on this check? Not debating, just trying to learn. 

[Blackstone45]

3 hours ago, HesedTech said:

The rule isn't really for safety purposes, it's to force competitors into a stock or near stock configuration. 

 

if this were true, it would only be applied to 'Production' guns.

 

I'm pretty sure the point of the disconnect is to prevent out of battery detonations?

[rowdyb]

 Put the stock hammer back in and I bet all will be fixed. 

[HesedTech]

28 minutes ago, Blackstone45 said:

I'm pretty sure the point of the disconnect is to prevent out of battery detonations?

Maybe that's the intent when it was written.
 

I went and measured my Shadow 2s at what distance the hammer would not drop when the slide is out of battery. The slide was 3.5 mm back when it would not drop with trigger pull. But there's a caveat, the breach was visibly open only 1.5mm.

 

The question then is how and where do they measure and is it consistent across brands of guns?

 

See how ridiculous this rule becomes. But it's the rule if you want to compete.

 

3 hours ago, Schutzenmeister said:

The measurement gap to which they are referring is the gap between the barrel hood and the breech face as @shred has indicated

At 1.5mmm gap from the face to the barrel hood on my gun it cannot be measure. Why? Because I can't get even a feeler gauge into the gap properly. I would like to see picture of someone measuring this.

[HesedTech]

3 hours ago, Schutzenmeister said:

 

I cannot possibly disagree more.

Why? Please explain.

 

Have you seen an out of battery in a CZ that was disastrous when the hammer fell? 

 

The only out of battery kabooms that destroyed the gun I have personally seen are with plastic striker fired guns. How do you measure those? 

 

Oh well this will turn into one of those blocked threads. I'm done.

[Schutzenmeister]

2 hours ago, IHAVEGAS said:

 

Are there any known incidents of people getting hurt due to a gun being out of specification on this check? Not debating, just trying to learn. 

 

In my personal experience, not exactly.  That dosen't mean it hasn't happened.  I have seen the damage a detonation out of battery can do.  These were caused by other factors though and not what we're discussing here.  Still ... I don't like the damage an uncontained exploding case can have whatever the cause.

 

The worst case of something like this was probably the USS Iowa in 1989 ... Open breech, detionation, massive explosions ... 47 (?) dead.  The Navy botched the investigation.  Bigger gun, but uncontained detionations should be avoided.

 

I've also on occasion witnessed a gun going full auto.  The shooter may or may not be able to control the muzzle rise in that case.  (I've seen that both ways.)  I don't know the root cause on those incidents, either.

 

47 minutes ago, Blackstone45 said:

if this were true, it would only be applied to 'Production' guns.

 

I'm pretty sure the point of the disconnect is to prevent out of battery detonations?

 

Badda-Bing, Badda (No)Bam!

 

22 minutes ago, rowdyb said:

 Put the stock hammer back in and I bet all will be fixed. 

 

That, or find a competent gunsmtih to fit things properly ...

 

11 minutes ago, HesedTech said:

Maybe that's the intent when it was written.
 

I went and measured my Shadow 2s at what distance the hammer would not drop when the slide is out of battery. The slide was 3.5 mm back when it would not drop with trigger pull. But there's a caveat, the breach was visibly open only 1.5mm.

 

The question then is how and where do they measure and is it consistent across brands of guns?

 

See how ridiculous this rule becomes. But it's the rule if you want to compete.

 

At 1.5mmm gap from the face to the barrel hood on my gun it cannot be measure. Why? Because I can't get even a feeler gauge into the gap properly. I would like to see picture of someone measuring this.

 

I assure you, that's STILL the intent today.  As to your Shadow ... I don't own a CZ so I can't intelligently address your question.  I haven't got one to experiment with.  However ... I have seen feeler wires ... perhaps you could try one of those.

 

Edit to add:

 

You might also consider the shaft of a drill bit of the appropriate size in your case.

Edited September 7, 2023 by Schutzenmeister

[Schutzenmeister]

6 minutes ago, HesedTech said:

Why? Please explain.

 

Because this test applies to ALL semi autos, not just your Shadow.  I covers ALL Divisions (except Revolver), even those where you have full permission to do anything to the triggers.  (Open, Standard, Standard Optics, and back in the day - Modified)

 

Edit to add:

 

Do we have to wait for someone to be injured or killed to add a common sense safety inspection prior to competition?

Edited September 7, 2023 by Schutzenmeister

[HesedTech]

59 minutes ago, Schutzenmeister said:

You might also consider the shaft of a drill bit of the appropriate size in your case.

You are pointing out the ridiculous of the 1.5mm measurement used by the OP IPSC's rule and it's only "approximately". 

 

 

Looked up the official rule:

It leaves it up to who ever is judging.  A lot of room to decide what the gap means.

 

Disconnector - Is mandatory and is checked by:

1. Cocking the hammer, and then

2. Open the slide until the gap between slide and barrel is approximately 1/16” or 1.5mm. ( The best guns fires only with zero gap )

3. Press the trigger. The hammer should remain cocked.
   (Any exception must be approved by the IPSC Council and published at the IPSC Website)

 

I hope the OP got his answer about how the system works on a CZ and other with similar mechanisms.

 

And yes, an out of battery discharge is bad (seen the results). However it's a bit hyperbolic to compare the battle ship accident.

 

And yes done with this thread.

 

Edited September 7, 2023 by HesedTech

[IHAVEGAS]

44 minutes ago, Schutzenmeister said:

Do we have to wait for someone to be injured or killed to add a common sense safety inspection prior to competition?

 

As a very general rule I think it is good to prove there is a significant problem before implementing a solution. I've participated in development of corporate and national safety standards for combustion systems, it gets frustrating because sometimes safety rules spring only from the imaginations of those who don't have to deal with the consequences of regulations, and the consequences in cost and performance and reliability can be severe. 

 

 

[Blackstone45]

Took it to my gunsmith, who fixed it by removing about 4 thou of an inch of material from the trigger bar.

[Runswithwood1]

On what part of the trigger bar did they remive material? I've recently gotten into tinkering with CZs and learning all I can