CZ455 HMR issue. Dangerous!

Dannyboy220

Active Member
Hi All..

Hopong someone can help me. I've got a CZ455 I'm 17hmr I bought it New in 2015 and I've probably done 1500 shots down it. The last time I took it out I was zeroing a new scope and had problems with the trigger/bolt.

When i pull the the trigger it's not reacting and there's no click of the pin. After waiting a few seconds I got hold of the bolt and as soon as it moved the gun went off.
I thought hangfire at first but tried another round and it did the same again, this time I stayed in position and gently moved the bolt. Bang! Off it went again.

Obviously that was the end of that night. I took it home gave it a clean and lubricated the bolt well. Tonight I've gone out, freshly cut today! Hoping it would be sorted but it's not. 2 shots both fired from touching the bolt.

Will take it to a Smith but wondered if anyone's experienced the same.
 

bobjs

Well-Known Member
sounds like the trigger needs adjusting,

or

the bolt has some crud in the firing pin channel, did you strip the bolt right down to its component parts? if not this could be the cause, rimfire rounds are very very dirty and can cause problems,

the only time time i have seen this happen was with a new rifle, but it’s not unknown for this to happen to a older rifle,

if you you are not confident in downing this then leave it to a smith, but when he has done it and before you pay your money ask him to do a drop test in front of you,( unloaded of course),

good luck

bob.
 

FISH BOY

Well-Known Member
Hi All..

Hopong someone can help me. I've got a CZ455 I'm 17hmr I bought it New in 2015 and I've probably done 1500 shots down it. The last time I took it out I was zeroing a new scope and had problems with the trigger/bolt.

When i pull the the trigger it's not reacting and there's no click of the pin. After waiting a few seconds I got hold of the bolt and as soon as it moved the gun went off.
I thought hangfire at first but tried another round and it did the same again, this time I stayed in position and gently moved the bolt. Bang! Off it went again.

Obviously that was the end of that night. I took it home gave it a clean and lubricated the bolt well. Tonight I've gone out, freshly cut today! Hoping it would be sorted but it's not. 2 shots both fired from touching the bolt.

Will take it to a Smith but wondered if anyone's experienced the same.


I have a 455 HMR and would interested in any explanation once sorted please.
 

25 Sharps

Well-Known Member
Hi All..

Hopong someone can help me. I've got a CZ455 I'm 17hmr I bought it New in 2015 and I've probably done 1500 shots down it. The last time I took it out I was zeroing a new scope and had problems with the trigger/bolt.

When i pull the the trigger it's not reacting and there's no click of the pin. After waiting a few seconds I got hold of the bolt and as soon as it moved the gun went off.
I thought hangfire at first but tried another round and it did the same again, this time I stayed in position and gently moved the bolt. Bang! Off it went again.

Obviously that was the end of that night. I took it home gave it a clean and lubricated the bolt well. Tonight I've gone out, freshly cut today! Hoping it would be sorted but it's not. 2 shots both fired from touching the bolt.

Will take it to a Smith but wondered if anyone's experienced the same.

Have you fitted a trigger kit?
 

Edinburgh Rifles

Well-Known Member
Does the trigger move freely when the bolt is out?
Any interference marks on the cocking piece (bolt underside) and sear (top side of trigger mech)?

Sounds like the trigger is hanging up and is not releasing
Releasing when the cocking piece to sear engagement is changed when you touch the bolt

Trigger shouldn't be lubricated
Bolts to a minimum (the lube more often than not picks up abrasive compounds and turns the lube into a grinding paste)

when you cleaned it was anything changed in the tension settings?
 

Dannyboy220

Active Member
Thanks so far guys. Some things to look at tonight.

No I haven’t totally stripped the bolt will have a look on YouTube later and see if I’m confident enough.
I did fit a trigger kit when 1st purchased and have had no problems.

Im not sure if it makes a difference but it doesn’t happen when I dry fire. I get the usual click of the pin on trigger pull which is set at about 2lb.

Edinburgh i I think you’re right regarding the sears. It’s definitely firing on the touch of the bolt but again only when live
 

gunner269

Well-Known Member
I’ve got 2 CZs both with trigger kits and never had a problem. If it only does it with a round in the chamber the chances are there’s a problem with the bolt.
 

25 Sharps

Well-Known Member
2 p worth you fitted a trigger KIT i'd look there first .

Absolutely, especially if shims are fitted.

first thing I would do is refit the factory trigger parts and see if the problem persists, I bet it doesn't.

I have fitted 3 trigger kits to 3 different 452s in 3 calibres, all failed bump test (properly dropped 12-15" on a concrete floor, safety off) with either shim and lightest spring, 2 failed on the medium spring. I've also bought one with a spring fitted that failed!!

Sounds like sear engageement is a bit off, ruling out the trigger Kit has to be the first port of call.
 

Tictac

Well-Known Member
If it's been ok for 1500 rounds a thorough clean and adjustment would be my first point of call. Strip the bolt as well.

Ive a trigger gauge if you want to borrow it, I'm 10mins from you.
 

kennyc

Well-Known Member
Strip the trigger and bolt and was them in lighter fluid that will also leave a residual amount of lube
 

foxandhound

Active Member
Dannyboy The only problem I have ever had with a BRNO or CZ in .22 or 270 calibre was a rusty bolt spring which prevents the bolt from impacting hard enough on the primer, touching the bolt might be sufficient to cause the bolt spring to move it just enough to detonate the primer. Strip the bolt which isn't difficult and check for rust/debris on the bolt spring, clean, oil and restore after checking the firing pin hole.

Regards foxandhound
 

linusr

Well-Known Member
Does the trigger move freely when the bolt is out?
Any interference marks on the cocking piece (bolt underside) and sear (top side of trigger mech)?

Sounds like the trigger is hanging up and is not releasing
Releasing when the cocking piece to sear engagement is changed when you touch the bolt

Trigger shouldn't be lubricated
Bolts to a minimum (the lube more often than not picks up abrasive compounds and turns the lube into a grinding paste)

when you cleaned it was anything changed in the tension settings?
Correct solution, should be fine after that
 

Dannyboy220

Active Member
Thanks for all your help guys, I've checked the trigger kit and that all looks in place.
Next I YouTubed and saw how easy it was to strip the bolt. Gutted and embarrassed that I didn't do it before. It's quite corroded, the spring was ok and the light dusting of rust came off. The components of the bolt are quite patchy now though where the corrosion was worst. I've blasted it inside and out with a solvent cleaner and it's cleaned up a lot but there's still the discolouration and I'm wondering whether it's going to be any better.

Can you buy new bolts?
 

Dannyboy220

Active Member
Red Dragon, absolutely right I'm a lazy git and don't look after my stuff. Never said it was the rifles fault (I love it!) just wanted some guidance on how to put it right.

Thanks for the help guys, will be back out on the stubble this week to see how it bangs
 
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