CZ457 light strikes, high power spring or modified firing pin?

[DonBayArsenal]

My CZ457 is experiencing light strikes with this new case of Eley Match. I think Eley might have changes something on new productions, the case head looks noticeable flatter and wider than the old ones.

My question is, to get better ignition, should I get a higher power firing pin spring or the modified firing pin based on y'alls experience?

Thanks!

 

[TubbyT223]

My CZ457 is experiencing light strikes with this new case of Eley Match. I think Eley might have changes something on new productions, the case head looks noticeable flatter and wider than the old ones.

My question is, to get better ignition, should I get a higher power firing pin spring or the modified firing pin based on y'alls experience?

Thanks!

Stock barrel or aftermarket barrel? Does it give light strikes with any other ammo?

What is the rim thickness. Actual measurement would be helpful.

 

[oldrifleman]

When was the last time you changed the firing pin spring? Does the nose of the firing pin still look good? The rim could be just enough different to highlight a worn ignition path.

 

[DonBayArsenal]

Stock barrel or aftermarket barrel? Does it give light strikes with any other ammo?

What is the rim thickness. Actual measurement would be helpful.

Aftermarket barrel, no light strikes until this new case of Eley match. Just measure that the rim thickness, old lot is 0.040- 0.041 inches and new lot is 0.038-0.039 so about 0.002 inches thinner and also quite a bit bigger in diameter.

left is old lot, right is new lot:

 

[DonBayArsenal]

When was the last time you changed the firing pin spring? Does the nose of the firing pin still look good? The rim could be just enough different to highlight a worn ignition path.

never changed the spring since new, I compared with another CZ457 which I bought this year and they look and feel about the same.

 

[walterg]

Aftermarket barrel, no light strikes until this new case of Eley match. Just measure that the rim thickness, old lot is 0.040- 0.041 inches and new lot is 0.038-0.039 so about 0.002 inches thinner and also quite a bit bigger in diameter.

left is old lot, right is new lot:
View attachment 8758082

It could be a headspace issue. Have you messed with the head space on the current barrel?

 

[TonyAngel]

I'll second checking headspace. Which barrel did you go with? If I recall, whidden gun works sells a very reasonably priced set of headspace gauges. I headspaced my lilja barrel to .043 for sk ammo and occasionally have problems with eley.

 

[TubbyT223]

Aftermarket barrel, no light strikes until this new case of Eley match. Just measure that the rim thickness, old lot is 0.040- 0.041 inches and new lot is 0.038-0.039 so about 0.002 inches thinner and also quite a bit bigger in diameter.

left is old lot, right is new lot:
View attachment 8758082

Dang that does look different. How old is the newest lot?

I also agree with Walter. Might be a headspace issue.

 

[bobby1028]

Any pics of one of the light strike rounds ? Rim thickness is within specs, what did you measure the rim diameter at, in comparison to your last lot. If the rim diameter was appreciably larger it wouldn't fit in the bolt face recess, causing serious extraction problems, if it could chamber the round and close the bolt at all. Not likely the case, I'd double check headspace...if already on the high side an extra .0002 could be the issue.

 

[DonBayArsenal]

Any pics of one of the light strike rounds ? Rim thickness is within specs, what did you measure the rim diameter at, in comparison to your last lot. If the rim diameter was appreciably larger it wouldn't fit in the bolt face recess, causing serious extraction problems, if it could chamber the round and close the bolt at all. Not likely the case, I'd double check headspace...if already on the high side an extra .0002 could be the issue.

forgot to get pictures when it happened but I've shown to a few people at the range and everyone agreed they looked like good strikes.

It chambers and extracts find BTW so I'm guessing that increase rim diameter is still within spec.

I didn't have an accurate way to measure the head space but it should be between .040 to .042 with the L3i barrel.

 

[DonBayArsenal]

Dang that does look different. How old is the newest lot?

I also agree with Walter. Might be a headspace issue.

New lot was bought this month, it was backordered so pretty sure is new production.

 

[Shifty6BR]

A bolt shim should take care of that..easy on, easy off.

 

[bobby1028]

forgot to get pictures when it happened but I've shown to a few people at the range and everyone agreed they looked like good strikes.

It chambers and extracts find BTW so I'm guessing that increase rim diameter is still within spec.

I didn't have an accurate way to measure the head space but it should be between .040 to .042 with the L3i barrel.

After 3 seasons of running a 457 action and much experimenting with head space and SD's I've settled at .042...runs Eley, Lapua and SK reliably

 

[DonBayArsenal]

Went to the range today and captured some pictures, left one didn't fire, right one fired. had about one FTF probably every 15 rounds ish, really frustrating.

BTW, I also measured the rim diameter, the new lot measures 0.272" and the old lot measures 0.267", so it's 0.005" larger in diameter, not sure if that can cause any issues.

 

[quintcarney]

I had the same issue with one specific lot of Eley match just this week. Let me see if I can figure out the lot #. I had F2F in both my CZ and Vudoo.

 

[TubbyT223]

Went to the range today and captured some pictures, left one didn't fire, right one fired. had about one FTF probably every 15 rounds ish, really frustrating.
View attachment 8758872View attachment 8758873
BTW, I also measured the rim diameter, the new lot measures 0.272" and the old lot measures 0.267", so it's 0.005" larger in diameter, not sure if that can cause any issues.

I’m no expert but those don’t look like light strikes to me. If I would have pulled that off a bench I would have thought it would have gone off

 

[Mistyrkool]

My CZ457 is experiencing light strikes with this new case of Eley Match. I think Eley might have changes something on new productions, the case head looks noticeable flatter and wider than the old ones.

My question is, to get better ignition, should I get a higher power firing pin spring or the modified firing pin based on y'alls experience?

Thanks!

These folks are great to deal with, give them a call...https://www.whiddengunworks.com/product/cz-457-modified-firing-pin/?utm_source=Main+List&utm_campaign=e25362a67e-EMAIL_CAMPAIGN_2025_09_02_12_11&utm_medium=email&utm_term=0_-e25362a67e-625655073

 

[DonBayArsenal]

I had the same issue with one specific lot of Eley match just this week. Let me see if I can figure out the lot #. I had F2F in both my CZ and Vudoo.

My lot is: 1025-06213. Let me know what’s your lot number. I believe mine was the latest production. I emailed Eley and they said their case head diameter should be consistent. I sent them the picture and my measurements so let’s see what they say. I’m impressed by how quickly they responded to my email, that’s always a good sign.

 

[p5200]

After 3 seasons of running a 457 action and much experimenting with head space and SD's I've settled at .042...runs Eley, Lapua and SK reliably

That's what I set mine at. Eley Match and SKRM have both functioned correctly. my Eley thickness measured 4 rounds at .040" and 1 round at .039"

 

[p5200]

Went to the range today and captured some pictures, left one didn't fire, right one fired. had about one FTF probably every 15 rounds ish, really frustrating.
View attachment 8758872View attachment 8758873
BTW, I also measured the rim diameter, the new lot measures 0.272" and the old lot measures 0.267", so it's 0.005" larger in diameter, not sure if that can cause any issues.

I'm also, getting 0.267"

 

[quintcarney]

My lot is: 1025-06213. Let me know what’s your lot number. I believe mine was the latest production. I emailed Eley and they said their case head diameter should be consistent. I sent them the picture and my measurements so let’s see what they say. I’m impressed by how quickly they responded to my email, that’s always a good sign.

Mine is 1025-06195 is the lot #

 

[DonBayArsenal]

Mine is 1025-06195 is the lot #

Can you measure the diameter of the case head of your lot when you get a chance? I'm trying to figure out whether that's only limited to my lot or was it across the board. Thanks!

 

[quintcarney]

Can you measure the diameter of the case head of your lot when you get a chance? I'm trying to figure out whether that's only limited to my lot or was it across the board. Thanks!

My lot measured .270 for me on the one i checked real quick.

 

[DonBayArsenal]

My lot measured .270 for me on the one i checked real quick.

hmmm, so it's all over the place for these newer lots.

 

[tomme boy]

Put a shim in the bolt and carry on.

 

[quintcarney]

hmmm, so it's all over the place for these newer lots.

You would think for $17 a box now it would be more consistent. But that’s just me.

 

[p5200]

The one box I bought at a lgs must be older lot. # 1023-05374 That's the only place locally that even sells them. Whether or not he'll order more when those are gone I don't know. He says no one buy them. I'd buy all he has if I could afford to. $20.59 per box seems high but, if no ones buying it I guess that's why. The SKRM shoots about as good but, I've only shot 20 rounds of the Eley it might improve still.