CZ 457 bolt shimming ?

[Topwater]

Has anyone had a marked improvement in accuracy by shimming the 457 bolt ? I have some Eley that shoots pretty well but has rims that are 2.5 - 3.0 thousands thinner than my other ammo. I have had roughly a 25% misfire rate with this Eley. I was wondering if shimming would eliminate these misfires. Thanks.

 

[boxs]

Have you measured your head space? I experimented with different head space and found no noticeable
improvement in accuracy. If you're getting failures to fire then head space may be your problem.
boxs

 

[Shifty6br]

Yes, shims should cure that...I had a
.17hmr that had a out the same amount of failurue rate..to fire, light strikes.

Was definitely a headspace issue.
Bolt shims made the problem go away and glad to say it is shooting well.

 

[mrh1958]

Has anyone had a marked improvement in accuracy by shimming the 457 bolt ? I have some Eley that shoots pretty well but has rims that are 2.5 - 3.0 thousands thinner than my other ammo. I have had roughly a 25% misfire rate with this Eley. I was wondering if shimming would eliminate these misfires. Thanks.

Shimming the bolt will not improve firing pin strike on the 457, so no, re-shaping the tip to strike just inside the rim edge will

 

[boxs]

I agree with mrh, reshaping the firing pin will improve how contact is made and reduce failures to fire. However, if your headspace is is too large it can absolutely cause light strikes and failures to fire. Check your headspace, simply shimming your bolt without knowing is not a good idea.

 

[J.d. Popkes]

I agree with mrh, reshaping the firing pin will improve how contact is made and reduce failures to fire. However, if your headspace is is too large it can absolutely cause light strikes and failures to fire. Check your headspace, simply shimming your bolt without knowing is not a good idea.

Agree

 

[dstoenner]

I used the shims and did reduce some flyers. Overall the groups were more consistent but it didn’t reduce the majority of the groups just the average of some of my ammo. Ammo that shot lights out still shot lights out

David

 

[Reddog58]

Correct me if I'm wrong but if you shoot in the factory class ,altering the firing pin is not in the rules !

 

[tmwinds]

Correct me if I'm wrong but if you shoot in the factory class ,altering the firing pin is not in the rules !

If you ain’t cheating you ain’t winning!

 

[Rwfish]

Correct me if I'm wrong but if you shoot in the factory class ,altering the firing pin is not in the rules !

Bolt or barrel shims are also not legal but the OP did not indicate if his plans are for Factory class competitions..