Author Topic: CZ 70 hammer not engaging sear when cycled manually  (Read 459 times)

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Offline noway

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CZ 70 hammer not engaging sear when cycled manually
« on: March 02, 2017, 06:23:34 AM »
I haven't played with my CZ 70 since I bought it, but some of the threads here had me taking a look at it and...

When I manually cock the hammer with my thumb, it engages the sear and remains cocked. When I manually cycle the slide, it does not.

I don't remember this being a problem when I first got it, so it's back to the range for a function check. One round at a time for starters...

Anyone else have this issue with their CZ 70 (or any hammer-fired pistol for that matter)?

(I'll post a video shortly...)

Offline noway

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Re: CZ 70 hammer not engaging sear when cycled manually
« Reply #1 on: March 16, 2017, 12:47:31 PM »
No video. I'm wondering if the spring isn't too powerful, and the slide isn't cycling back far enough to catch the sear or engage the disconnect when it returns to battery?

It alternates between being a nice DA/SA or a nice DAO...

I am going to try another recoil spring, as the stock spring and milsurp replacement were both about twice as long as the barrel.

Offline czechollector

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Re: CZ 70 hammer not engaging sear when cycled manually
« Reply #2 on: March 16, 2017, 03:28:33 PM »
What ammo are you using?  Seems I recall S&B is loaded a little hotter than most American.  Might make a difference.

BTW, the spring on mine is just a little short of twice barrel length.
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Offline noway

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Re: CZ 70 hammer not engaging sear when cycled manually
« Reply #3 on: March 16, 2017, 04:19:07 PM »
What ammo are you using?  Seems I recall S&B is loaded a little hotter than most American.  Might make a difference.

BTW, the spring on mine is just a little short of twice barrel length.

S&B ball. And we must have the same spring...

Offline NickySantoro

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Re: CZ 70 hammer not engaging sear when cycled manually
« Reply #4 on: April 02, 2017, 06:18:37 PM »
Just a thought. If the spring is too long, even when fully compressed it may not allow the slide to retract far enough to cock the hammer and engage the sear. If you remove the spring, will the slide then retract far enough?

Offline noway

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Re: CZ 70 hammer not engaging sear when cycled manually
« Reply #5 on: April 02, 2017, 10:05:56 PM »
Just a thought. If the spring is too long, even when fully compressed it may not allow the slide to retract far enough to cock the hammer and engage the sear. If you remove the spring, will the slide then retract far enough?

It might be something like this, but I fear a tear-down is called for. It's a nice-shooting gun, and the DA isn't bad, but obviously something needs work...

Online Grendel

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Re: CZ 70 hammer not engaging sear when cycled manually
« Reply #6 on: April 02, 2017, 11:18:24 PM »
Does it engage the sear and cock the hammer under recoil? If it does, then maybe clipping a couple of coils off the recoil spring is all you need to do.
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Offline NickySantoro

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Re: CZ 70 hammer not engaging sear when cycled manually
« Reply #7 on: April 03, 2017, 08:31:43 AM »
Just a thought. If the spring is too long, even when fully compressed it may not allow the slide to retract far enough to cock the hammer and engage the sear. If you remove the spring, will the slide then retract far enough?

It might be something like this, but I fear a tear-down is called for. It's a nice-shooting gun, and the DA isn't bad, but obviously something needs work...

Try racking the slide without the spring and post back. Five-minute test.

Offline noway

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Re: CZ 70 hammer not engaging sear when cycled manually
« Reply #8 on: April 03, 2017, 08:25:12 PM »
 :-[ After I stripped this down to the frame, I reassembled it with the sear spring hooked over the top of the sear. I didn't have a schematic, and I couldn't remember what it looked like when I took it apart.

A minute with the needle-nosed pliers and I got it seated properly. Now it's 100%.

Live and learn.

I do not plan on ever taking it apart again...  :D

I have to say that the CZ-70 is a very nice shooting .32, esp. compared to the Beretta Tomcat I once owned, which was sharp and unpleasant for such a small cartridge.
« Last Edit: April 03, 2017, 08:26:49 PM by noway »