Scorpion Light Primer Strikes

[motorolanut]

Good to hear you WWB success.  Do you prefer the 115 or 124?

[jc44208]

Thanks for all of the additional replies.  Sorry I've been so long with an update.

I took the bolt apart and inspected and cleaned.  I didn't see anything that would cause a problem.  Unfortunately I did this before reading the post about the firing pin safety block.  Nothing stood out but I wasn't looking for that problem specifically.  There were no gummy oils or greases.  Everything was very clean with a very light oil.

I got a chance to go out and shoot 50 quick rounds this morning.  This was S&B 124 grain fmj.  The failure rate was down to only 1 in 50 on that particular box.  The cartridge that failed to fire did fire on the 2nd try.

I don't have a stock scorpion trigger to compare it to but the hammer does feel on the weak side to me.  There is practically no force left in the spring by the time the hammer reaches the vertical position.  I may contact CZ or CZ Custom and see what they recommend. 

Here are some images of the marks left on the primer.   Scorpion on the left.  P10C on the right.

[jc44208]

The P10C brass was from S&B and the Scropion was the Winchester Nato, so that's not an apples to apples comparison.

[brisix]

I had a very similar thing happen.   I tracked it down to a broken hammer spring.  Below is my post on the issue.

https://czfirearms.us/index.php?topic=104129.0

[DanT]

IF the spring is not cracked or broken, you could try trying to "unwind" it a few degrees.

For the trigger spring that is so darn heavy, a few people have used plyers to "force" the legs closer together when not in use.  This reduces the spring force when in operation.  "Unwinding" the hammer spring a few degrees is the opposite, trying to get the "leg" and "hammer" sections a bit further apart in order to make the force a bit stronger.

- Dan

[shootingsight]

My cases looked exactly like that.  Makes me even more sure it is the firing pin block.

As stated, take it out (for testing only), and your problem will disappear.

[Due51]

It might be something as easy as a reduced power Firing Pin Return Spring and Reduced Power Plunger Spring.  If lighter trigger and hammer springs were installed you might not be getting enough ooomph to the firing pin.
(Case in point: when installing a CGW reduced power mainspring into a CZ pistol, you are warned to "never change the hammer spring only or misfires are certain")