CZ Shadow 2 Half Cock in rapid fire or racked vigirously.

[EZ128]

About 10K rounds. Comp Hammer. Comp Disconnector. Original Sear. 10% less power sear spring. All were working perfectly but started to go half cock in rapid fire ( anything less than 0.50 split). I can simulate it by racking it vigorously.

See video here: https://youtube.com/shorts/ADA88UBZx_M?feature=share

When racked in a "normal " way  ( or in slow shooting), the hammer will not follow or go into half cock. Even when pushed hard, it will NOT fall or follow.

I guess this is either a timing issue? Would like to understand it before replacing the hammer/sear/spring etc.

Thanks!

[Andres B]

Replace your minus 10 sear spring with original or Tanfoglio one. Using too soft sear spring is a bad idea anyway IMHO.
if that doesnt work, try original disconnector.

[Wobbly]

Thanks for the very clear video.

I'm with Andres B. Re-install the original sear spring.

[SI VIS PACEM PARRABELLUM]

Yeah the problem with springs is over time they lose tension and a reduced power spring is already starting out at a disadvantage. Unless you find something gunked up or otherwise not moving freely I'm with the rest. Change back to the stock sear spring.

[tdogg]

How tight is your overtravel screw set on that trigger?  It needs to be setup to not allow the hammer to contact the sear at all when the trigger is fully depressed.

I'd like to see the sear face and hammer hooks.  Unless your sear spring is worn out, then my money is on the sear getting rounded off by hitting the hammer hooks.

Cheers,
Toby

[EZ128]

Thanks Guys: I couldn't find the original factory sear spring ...but I put the original Shadow hammer back and can't seem to reproduce hammer follow by racking it really hard now. Also took pictures of the old comp hammer (really worn). Anyway I'd need to test it again with live rounds. If that works, will try new sear spring. Will report back.







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[SI VIS PACEM PARRABELLUM]

Wow that hammer looks absolutely beat! Who's the manufacture of that part? I have CGW hammers in all my CZ's and more than a couple with well north of 10K rnds and they look pristine compared to yours.

[EZ128]

This is a CZ brand ...I did have lots of more dry fire with it using CoolFire ( gas-powered slide movement) tho.

On another note: I wonder if anyone tried to revive an old hammer by sharpening the edges??? Probably not too wise to do so?

[Andres B]

 Dunno, those hammer hooks dont look terribly worn...
 Sear must be far worse. For laughs n giggles, just change the sear.
 Installed the same hammer once for one friend, didnt like it, too little engagement. Did not like the fact, that this hammer upper part is narrower also. Had to make more engagement by filing down the part of hooks sear is sitting on when hammer is cocked. Like 0,1 mm or so.
 Installed CZ SA hammer on my SP01 shadow, which developed hammer follow like 15-20k rounds later. Changed the sear and the very same hammer is still very much OK.
 Somebody mentioned poor adjustment of the overtravel screw ruining the sear/hooks. This might be the case also. You should have at least 0,1-o,15mm between hammer hooks and the sear.
 Do not try to ,,sharpen,, the hooks if you dont know exactly what you are doing.
 Usually installing comp hammer also means fitting the sear.
 zendl.cz also makes comp hammers for less money. Looks like you have Eemann trigger in your toy, so you are probly from Eastern Europe?

[tdogg]

I agree that hammer doesn't look all that bad.  The tops of the hooks have some polishing which might indicate the sear rubbing across the hook?  What about the sear?  Did you inspect the face of the sear that interfaces with the hammer hook?

Love the peening on the face of the hammer from the firing pin impacts.  That has seen some use!

CZ only case hardens their ignition parts.  If you remove any metal from the hook you will remove the hardened metal and will be left with soft steel that will deform over time.  Same goes for the sear face, just replace it if worn.

Cheers,
Toby

[EZ128]

I am actually from Canada: it is way more difficult for me to get parts out of US than from Europe. Hence the ET parts.

Didn't pay much attention to trigger over travel screw or the sear spring before: will pay more attention and compare when I get new parts back. The hammer is free moving when the trigger is pull pressed though.

Here are some pictures of that sear when pulled out of the gun (no cleaning was done )









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[Andres B]

 Yeah. Sear edge looks bit rounded.

[tdogg]

Is that gunk built up on the edge of the sear or is that the edge rolled over?  If that is rolled over metal, then you have a found your problem.  I wouldn't expect it to span across the entire sear face and hence the question.  I wonder if it is catching the half cock ledge on the hammer when falling?

Before shooting with new parts you should definitely back off the over travel set screw.  Adjust it using this tutorial:  https://cdn1.cajungunworks.com/wp-content/uploads/2020/07/28155351/How-To-Adjusting-Trigger-Screws.pdf

Cheers,
Toby

[SI VIS PACEM PARRABELLUM]

If it were mine I'd replace the hammer and sear and probably go ahead and re-spring the gun overall since it's apart at this point. Both parts show enough wear that I wouldn't waste time doing piecework. Cajun Gun Works has some very good quality hammers/sears and so on. They do have an international distributor who should be able to fix you up should you decide to go that route. https://cajungunworks.com/international/

[M1A4ME]

If it were mine I'd replace the hammer and sear and probably go ahead and re-spring the gun overall since it's apart at this point. Both parts show enough wear that I wouldn't waste time doing piecework. Cajun Gun Works has some very good quality hammers/sears and so on. They do have an international distributor who should be able to fix you up should you decide to go that route. https://cajungunworks.com/international/

Don't know much about guns but on car engines, if you replace parts of a worn assembly with a new part it will wear both parts (old and new) much faster than if you'd installed two new parts to work with each other.

I'd vote replacing both the hammer and sear (and the sear spring, even if you buy/install a new lighter than stock spring.)

Good luck with it.