CZ457 Trigger issue.

[Cogswell & Harrison]

The back story is that a little while ago I picked up a nice second hand 457 in .22 WMR. I've shot it a few times but always felt that the trigger was on the heavy side and measuring yesterday it came out at 3lb 2oz, no first stage to speak of and no discernible over travel. Looking at and adjusting the main adjusting grub screw, the one with the locknut, makes no difference to the situation and in fact, the screw can be removed altogether without changing the pull weight. The trigger can be best described as "dead" with no feedback nor prediction of breakpoint, just like pulling stiff lever really.

The previous owner indicated that he was happy with the trigger and felt no need to change things, myself I'm not so sure that he or someone has not had a go. I have an inkling that there is some conflicting interaction twixt the first stage/pre-travel adjustment and the overtravel adjustment, (sear engagement?).

Thoughts would be welcome please, and maybe on the order in which adjustment should be done first, second and third. I'm not averse to having a go and rest assured that I'm old enough and ugly enough to not risk an unsafe situation.

Thank you.

 

[Smellydog]

Back the over travel screw off. Sounds like someone has the over travel to tight which incidentally has nothing to do with sear engagement.
It's a single stage unit. There is no first stage.

The weight spring is captive. To replace it watch videos.
I replaced mine with a smaller diameter one so it's no longer captive and can be removed easily.
By the way, I bet there are plenty of videos on setting a 457 unit up by now.

 

[Cogswell & Harrison]

Back the over travel screw off. Sounds like someone has the over travel to tight which incidentally has nothing to do with sear engagement.
It's a single stage unit. There is no first stage.

The weight spring is captive. To replace it watch videos.
I replaced mine with a smaller diameter one so it's no longer captive and can be removed easily.
By the way, I bet there are plenty of videos on setting a 457 unit up by now.

Thank you, I'll give that a go. I've had look at a few videos but found them to be lacking in detail, especially regarding the consequences of one adjustment affecting another if you see what I mean.

 

[Smellydog]

Thank you, I'll give that a go. I've had look at a few videos but found them to be lacking in detail, especially regarding the consequences of one adjustment affecting another if you see what I mean.

Yeah.
The over travel feature is best backed off.
Once the the other settings, the weight is good and sear ( I just forget what it's like, not looked for ages) then bring the over travel in but not much.
I think some over do the over travel thing.

 

[Cogswell & Harrison]

Yeah.
The over travel feature is best backed off.
Once the the other settings, the weight is good and sear ( I just forget what it's like, not looked for ages) then bring the over travel in but not much.
I think some over do the over travel thing.

Thank you again. The screw you mean being the number 51 in this drawing on RF Central? I'm more guided to follow your advice by the way.

CZ 457 TRIGGER DRAWING

This is my drawing of the CZ457 trigger and how it works for those who are new to the CZ457. This will show the trigger how it works and what each screw does. HOW TO ADJUST THE CZ457 TRIGGER 1- Adjust sears engagement screw #49 in until it won't hold, then turn out until it holds. 2- Adjust...

www.rimfirecentral.com

 

[Heym SR20]

A nice crisp 3lb pull is about perfect on a hunting rifle.

 

[Smellydog]

Thank you again. The screw you mean being the number 51 in this drawing on RF Central? I'm more guided to follow your advice by the way.

CZ 457 TRIGGER DRAWING

This is my drawing of the CZ457 trigger and how it works for those who are new to the CZ457. This will show the trigger how it works and what each screw does. HOW TO ADJUST THE CZ457 TRIGGER 1- Adjust sears engagement screw #49 in until it won't hold, then turn out until it holds. 2- Adjust...

www.rimfirecentral.com

Yes, back that out and then you can feel the trigger other adjustments better.
Put differently, eliminate it's affects while you adjust the others.
I wind the sear until the adjuster trips it, then back out until you are happy with it but do a good bump test. Bang the butt on the floor.... without breaking it of course.

 

[Cogswell & Harrison]

Okay, an update with no positive outcome. I tried backing off the overtravel screw and whilst this freed up the trigger blade movement somewhat it made no difference to the amount of trigger pull weight, (3lb 4oz), despite the trigger pull weight adjustment screw being removed altogether.

I've concluded that there is something amiss within the housing itself and I don't really feel confident going any further so I'm going ask local gunsmith to have a proper look.

 

[Smellydog]

Okay, an update with no positive outcome. I tried backing off the overtravel screw and whilst this freed up the trigger blade movement somewhat it made no difference to the amount of trigger pull weight, (3lb 4oz), despite the trigger pull weight adjustment screw being removed altogether.

I've concluded that there is something amiss within the housing itself and I don't really feel confident going any further so I'm going ask local gunsmith to have a proper look.

Did you adjust the sear until it clicked off?

 

[Smellydog]

It's starting to sound like it needs a lighter spring .
Remove the housing.
Get a block of wood, drill a hole in the wood.
Drift the trigger pin into the hole. This protects the ally housing.
Remove spring.
Refit and add the new spring I can send you from the screw side once rebuilt.
Pm me if you want a spring.
Once done you won't ever need to take apart again.
You'll get around 2lb trigger.

 

[Cogswell & Harrison]

Did you adjust the sear until it clicked off?

That's the one enclosed within the trigger blade and accessible from outside when the rifle is assembled? Yes, I adjusted that one out until it was protruding well outside of the blade assembly itself, should I have kept on going further until the firing pin dropped?

 

[Smellydog]

That's the one enclosed within the trigger blade and accessible from outside when the rifle is assembled? Yes, I adjusted that one out until it was protruding well outside of the blade assembly itself, should I have kept on going further until the firing pin dropped?

You screw that one in to lessen the seat engagement. You may of increased it.
Try it the other way.

 

[Cogswell & Harrison]

You screw that one in to lessen the seat engagement. You may of increased it.
Try it the other way.

Result! It was me who confused the direction of travel with the adjustment of this screw. Slowly screwing this one in until the sear disengaged then backing out half to three quarter turn has cured the 3lb 4oz pull weight. There's a small opening to view what is going on with this adjustment so as not to create an unsafe situation, I've carried out a thorough series of bump and slam fire tests and all is good.

I've concluded that the new safe pull weight of 2lb 4oz is about where I need it to be, it's crisp and predictable so I can ask no more from a hunting set up. Thank you for your help and assistance. Just one last thing, maybe I ought to have placed this thread in the gunsmith section!

 

[pimmy]

Rim ride magic in Barnsley do trigger spring kits there cheap as chips easy to install and work great had a few on 17hmr

 

[Onearmedbandit]

Hi there, I replied to this before however I had the posts removed as I was offering to sell stuff. I am not of high enough status to be able to post the bits for sale.
There can be a few issues with the trigger.
1, If it has been removed before some people put the pivot pin back in with a sledge hammer and missing the pin. Smashing the "trigger housing" inwards and causing friction or a pinch with the trigger pull.
2, You need a reduction springs. Caliber pros is very good.
3, Check the pivot pin in not causing you issues.
4, Check that all adjustable screws are still in good order and nothing has been crossed threaded or over tightened.
5, Have a look at the trigger shoe it's self. Check it is made properly no burrs or anything that needs filing or knocking back. (Mass production and all that.)
6, check the spring postion is correct. A dab of grease can help.
If you still need some help drop me a message and I will help if I can. The reduced power spring can reduce the trigger pull weight by upto 50%. 10 minute job at home with a hammer and a 3/32 punch.