Light strikes with CZ-75B

[kirbinster]

I have a CZ-75B with competition hammer and springs from CZ Custom that has worked flawlessly for me until recently. I have had occasions where in single action the hammer would come down but no kaboom. I would then pull the trigger again in double action and the round would fire. Never thought much about it, until this weekend as it was a random and rare occurrence. I had it happen on three out of four stages at an IDPA match this weekend. Was shooting in SSP so first shot was double, then the failure, then double and then it worked fine the rest of the stage in single action.

I am assuming that perhaps the hammer spring might need replacing. Any other suggestions? If that what is involved in changing it out. What weight spring should I look to replace it with. If I have to tear it apart is there anything else I should be changing? Obviously if I can get a lighter trigger pull while at it that would be a positive as well.

[bigmatt]

Do you have an extended firing pin? No-get one Yes-then the 11.5 lb hammer spring is what you want.

[cnote]

You want the extended firing pin first if its not in there

Then a new 13 lb should reliably ignite all primers

An 11.5 most and a 8 federals only

Edited April 21, 2015 by cnote

[kirbinster]

Do you have an extended firing pin? No-get one Yes-then the 11.5 lb hammer spring is what you want.

That is a good question. I bought the gun about a year ago and it was lightly used, so I am not sure. Is there a part number on the pin or an easy way to tell by looking? If I call CZ Custom would they be able to tell me from the serial number how they sold it?

If it matters I am using Freedom Munitions 147gr new ammo, not the reloads.

Edited April 21, 2015 by kirbinster

[cnote]

Yes they can by description of it and a length with a caliper

You could also take a pic of it an post on here, someone ( perhaps EERW)

Will have and answer in short time

[brisix]

More than likely you have a 13lbs OEM spring with 2 coils cut unless you asked for the competition trigger job. The 13lbs with 2 coils cut should still work on all primers. I would recommend replacing the hammer spring with CGW 13lbs if you want to pop all primers. The CGW 11.5 lbs and 8lbs give you a very light and awesome DA trigger but you are limited in primers you can use. I replace my hammer springs at the end of each shooting season or if I get a lot of light primer strikes. I run the 13lbs CGW spring.

Very simple to replace. YouTube is your fired with any disassemble.

Primer seating depth can cause this too. Less likely with new Freedom Munitions ammo.

[cnote]

stolen from another blog, i believe these are for a B model with the flat for it

Edited April 21, 2015 by cnote

[thompsoncustom]

Any idea if it has a lighter firing pin block spring?

The hammer is furthest rearward in SA thus hitting a little harder than in DA so my thoughts are the primer is not seated deep enough or maybe the firing pin block is getting stuck and the first shot drops it. Just something else for you to look into.

Edit: never mind just seen your not using reloads so that should rule out the primer. Doesnt mean a good detail strip/cleaning its in order.

Edited April 21, 2015 by thompsoncustom

[eerw]

Are the primers marked on the light strikes?

any change to gun? what are you cleaning and oiling/greasing with?

have you pulled out FP and cleaned out channel?

have seen instances where light strikes and turns out people using a sonic cleaners and oil and grease built up in FP channel restricting FP movement.

other issues..make sure the block is lifing high enough to let FP move also.

[kirbinster]

Don't know if there are marks on the primer from light strikes as this happened in a match and I just pulled the trigger again and it fired in double action each time.

I had pulled the firing pin about a month ago and cleaned the channel out completely. I had actually used brake cleaner to clean it out. Kept spraying it in there and used a Q-Tip until the fluid came out clear.

How do you check the block to make sure it is working correctly?

[jdd817]

I had an issue in my gun where while shooting it seemed like I was getting light strikes, but the actual problem was a false reset - the sear trigger bar would clear the sear but not the firing pin block, so when I pulled the trigger it would release the hammer but the firing pin wouldn't actually move. The solution was to adjust the spring underneath the trigger bar such that there was more pressure on the right side of the trigger bar than the left.

Try dry firing it, then rack the slide with the trigger still fully back, then let the trigger forward as slowly as you can until your finger comes off - if you can feel two clicks then that may be the problem rather than light strikes.

[motosapiens]

new springs.

my 75b started giving me occasional light strikes. It appeared to me the slide was stopping about a mm from being fully in battery, so on the first strike the slide would move just a smidge, and on the 2nd the primer would go off. I replaced the very very old recoil spring and the problem went away.

fwiw, I was never able to get 100% reliable ignition with an 11.5 lb spring, so I use a 13lb hammer spring.

[kirbinster]

Thanks jdd817 - I tried as you suggested an only feel one click.

Motosapiens - The gun currently has a 15 pound hammer spring. I am going to replace it as it is probably worn, would you suggest I go with 13 pounds then? What about the recoil spring? What weight should I get if I am using 147 grain ammo? I think I am going to also get the extended firing pin unless someone can give me a reason that might be a bad idea.

[kirbinster]

Ordered an extended firing pin, new firing pin spring, 13# main spring (it had 15# and CZ Custom suggesting sticking with 13 rather than 11.5) also ordered new recoil spring. Hope that fixes it as this is one of my favorite guns and it needs to be reliable again.

[GeneBray]

What ammo are you using? Reloads? Have you checked primer seating depth? Back from the Dead's suggestions are very good. I would start with pulling the firing pin from the slide and cleaning all the parts and channel very well. Maybe replace FP spring. Consider a complete disassembly of the lower and complete cleaning as well. How many rnds through the pistol? I doubt the main spring is bad, but it may have broken. Replacing it may solve the problem. I use a CZ Custom extended firing pin and 8 lb. main spring. Only primers that don't go bang reliabily are Wolfe/Tula. But I have to keep thing clean and lubed regardless of primers. Always do the cheap and easy fixes first before spending money. Cleaning and lub is always a cheaper fix to a problem than buying parts you don't need.

[kirbinster]

What ammo are you using? Reloads? Have you checked primer seating depth? Back from the Dead's suggestions are very good. I would start with pulling the firing pin from the slide and cleaning all the parts and channel very well. Maybe replace FP spring. Consider a complete disassembly of the lower and complete cleaning as well. How many rnds through the pistol? I doubt the main spring is bad, but it may have broken. Replacing it may solve the problem. I use a CZ Custom extended firing pin and 8 lb. main spring. Only primers that don't go bang reliabily are Wolfe/Tula. But I have to keep thing clean and lubed regardless of primers. Always do the cheap and easy fixes first before spending money. Cleaning and lub is always a cheaper fix to a problem than buying parts you don't need.

I am using new (not reman) Freedom Munitions 147gr 9mm ammo. I have pulled the firing pin and cleaned everything very well and run the gun fairly wet. Have not totally taken the lower apart, but if parts don't work that will be the last step. The gun has about 5,000 rounds through it, if I believe (which I do) what the original owner told me when I bought it a year ago.