Please let us know how the testing goes

 

Will do! I just ordered the YoDave Plus 10 striker spring as CZ USA does not have factory springs listed for the CZ455.

 

Changing the striker spring can make a difference providing the one in the rifle has taken a set and isn't doing the job it was intended to do.

If the spring used was properly designed for the job it shouldn't ever take a set and should pretty much last for the life of the gun (ex. Holeshot/PQP 2500X or Trident). Unfortunately, as we all know, that's not always the case

And, IMO, one smaller group after changing the spring is hardly evidence that the spring change caused the groups to shrink. It could be the cause but so could a bunch of other things

 

That is rather interesting. Any inference as to what would cause the groups to differ? Just consistency of primer ignition, maybe?

 

Tried the 10% stronger spring in my mtr, change it back since it made my trigger pull harder.

 

They can make the bolt more difficult to cock too. Along with creating more vibration. Stonger spring is not what I'd go with. If I did I'd probably cut a few coils and grind the end flat or I'd pre-relax the spring and then test to make sure I'm getting enough depth on the strike and that it's consistent.

For the most part, most rifles probably don't need the spring changed if they're stored with the bolt uncocked

 

This information is from an Email campain with Widden Gun Works. They are offering the springs from their web site. Is this a necessary improvement? Not necessarily. Your main improvement is with the proper ammunition.

Striker-Firing Pin Springs - Whidden Gunworks

At the Whidden Gunworks Test Range, we've surely seen the importance of a fresh striker or firing pin spring. We have solved accuracy problems on a

www.whiddengunworks.com

 

Wow, they suggest changing the spring once a year….seriously, after over 45k shot with mine still got the original one and it work well…..😳

 

I share the skepticism being expressed by some of you. However, Whidden is pretty well respected supplier and for the cost of a spring I can't see anything being lost by testing the theory. I am sorry to hear about the YoDave spring, but it was the only game in town right now. We shall see what we shall see

 

I have nothing against the folks at Whidden but they are in the business of selling stuff. I won't say I've never changed a striker spring, I have, but they were on rifles that were sitting in storage cocked for years (Kimber 82G) or otherwise suspect.

The Turbo RFBR actions and their clones are notorious for their striker springs not lasting very long. So after buying a well-used 10X I went on the hunt for replacement striker springs. After reading a post from Stiller about how to relax a Turbo spring, I went ahead and did the process to the spring that was in it when I received it. I'm still using that same spring a couple cases of ammo later. I took it out an measured it before a big match recently and it's still at the same length. I have a few replacements if I ever need them but I'm not sure I ever will

After buying my CZ 452 American several years ago I ordered a spare striker spring for it. It's still sitting in my parts box. I store all my rifles with the bolt uncocked. The rifles shoots as well today as it did when I bought it 15 years ago

 

Snake oil. Also, two cherry picked "before and after" groups are meaningless.

BUT....if you are convinced that a replacement spring can cut your groups in half, I have some oceanfront property in Arizona I'd like to sell you.

 

I hear sales are slow right now. I do change shocks in my trucks every 5 years.

 

In the rifles I have done it too, I haven't seen a difference. In group sizes or primer hit. That said, several of my best cz's shoot as well as an old anschutz 64 match I have. And the Annie's have a much better firing pin hit. If you store the rifle decocked I would say the $ is better spent on ammo

 

Who stores their rifles cocked???? 🤪

 

A lot of people who don't know any better

 

I would think the minimum force needed for consistent ignition would be the way to go......I maybe wrong though.

 

It's a well known fact for a century that it takes X amount of force to efficiently ignite a primer.
25 ft lbs i believe is the standard minimum.
Not saying that 24 ft lbs won't ignite the primer but extensive testing over the decades has proven better ignition eqauls better consistency in the ammo.
Your ammo of choice may be a eley product.
And can't find a comparable lapua product.
Being how the brass alloy as well as rim thickness is different between those two ammos.
A "smart man" would realize that one ammo with softer alloy will perform best with 28 ft lb strike.
While the other ammo performs best at 26 ft lb..
There's a reason firearm manufacturers have from 26-32 ft lbs springs.
Keep on shooting!

 

Millions of hunting firearms, have been and still are, stored for decades, a year at a time, yet they still go bang every time when hunting season comes around. Much ado about nothing. How much is that waterfront property in Arizona?

 

I think some are comparing apples and oranges here. Hunting guns aren't capable of producing the before group let alone the after in the original post. Competition guns are usually setup with as light a set of springs as possible in order to reduce trigger weight. We used to see problems caused by this in major 9s and 38Supers as they'd get the firing pin spring too light and inertia would allow the pin to rebound enough to at least dimple the primer as the slide closed if not detonate it. When dealing with a spring that is already intentionally at the very minimum strength to get the job done, it takes a lot less time and cycles to begin to wear. The other consideration is the spring doesn't have to outright fail to ignite the round. Any increase in lock time will likely result in a larger group size as the rifle has more time to move during the firing cycle so a spring that takes 1/100th of a second longer to drive the pin forward could indeed be impacting group sizes. Most of us will likely never be able to tell the difference as our own ability stops well short of what the rifle is capable of if all else was perfect, but that doesn't mean the logic is wrong, just that the likelihood of that dramatic a result isn't particularly high.

 

We are not talking about "going bang" but rather does the striker spring loose enough force to provide consistent and full ignition which we know can affect accuracy.

 

I've read remarks by CZ guys with more experience than me that one should change his 45X series firing pin springs every 5,000 rounds.
Any thoughts?

 

Every case of ammo sounds like a lot. I have way more than that in my 452 American and I've never changed it. It would be helpful if someone could document the length of the spring as new and then the length of the same spring after it's been used for 5000 rounds. If it's significantly shorter and producing inconsistent ignition then I would change the spring

 

Who stores their rifles cocked???? 🤪

A lot of people who don't know any better

ok, I'll be the guy to go out on a limb - am I missing something? What am I missing ? The bolt it cock-on-opening, no? Last time I looked, and IIRC, when I put the rifle back in the safe with the action open, as many of us do, the bolt is in the cocked position. Most here are referring to closing the action with a cocked firing pin, but either way, the firing pin is cocked.

FWIW, to store "uncocked", I close the action while holding the trigger to the rear.

 

ok, I'll be the guy to go out on a limb - am I missing something? What am I missing ? The bolt it cock-on-opening, no? Last time I looked, and IIRC, when I put the rifle back in the safe with the action open, as many of us do, the bolt is in the cocked position. Most here are referring to closing the action with a cocked firing pin, but either way, the firing pin is cocked.

FWIW, to store "uncocked", I close the action while holding the trigger to the rear.

I don't think you're missing anything.

Hold the trigger back as you close the bolt. Now the bolt is stored uncocked with the bolt closed as you mentioned

 

I think the "fresh striker spring" idea would be better supported by chrono data, background info on old spring, cleanliness of striker system and ammo that has vetted velocity vs "fresh spring" with all these things beeing the same. If there is a consistent reduction in es then we have real, potentially useful, data. This still won't guarantee improved accuracy but should help. ??

 

Image related

 

I would think there would be more to be gained in a cz by sharpening the firing pin tip so it doesn't create such a flat hit. You can definitely tell a hit from higher end rifles vs more mass produced stuff. Spring pressure is only one aspect

 

Now you are able do drive yourself even farther off the deep, deep, deep end. May be a short or long trip it all depends on you. Should keep you busy for the next few years. Have fun!

A coil spring's weight is typically measured by calculating its "spring rate," which is the amount of force required to compress the spring by a specific distance, usually expressed in pounds per inch (lb/in) or Newtons per millimeter (N/mm); essentially, a higher spring rate indicates a stiffer spring requiring more force to compress it by the same amount.

Key points about measuring coil spring weight:

• Calculation method:
  To measure spring rate, you can place the spring in a spring rate tester, apply a known force, and measure the resulting compression distance.
  
  
• Units:
  Spring rate is usually measured in pounds per inch (lb/in) in the imperial system or Newtons per millimeter (N/mm) in the metric system.
  
  
• Factors affecting spring rate:
  The spring rate depends on the wire diameter, coil diameter, number of coils, and material used to make the spring.

Try this site as well. Should keep you busy for a little while. Bye Bye.

How to Calculate Spring Weight

Definition: The calculation of the mass weight of a coil spring based on its wire size, outer diameter, number of coils, and density of wire. Can be calculated using the corresponding formulas and equations.

www.acxesspring.com

 

Most firing pins are inertia driven by the spring in the bolt and they just need to get the firing pin up to speed to do the work. Provided it's doing it's job consistently there's no need to change things in most rifles and they will likely last a lifetime. If there is a problem springs can solve changing them won't hurt.

I was once informed that the compressing and decompressing of the springs is what weakens the springs and leaving a mag filled or hammer cocked should would not weaken the spring...I don't know if that is true or not?

However, one thing is for sure, the firearm/accessory industry is rife with solutions looking for a problem.

As Pat mentioned: Hold the trigger back as you close the bolt. Now the bolt is stored uncocked. I do that on my bolt rifles.

 

Did some miss what wiljen posted? Heavier spring weight is not about hitting the primer harder, it's about lock time. Some of your more accurate rimfire rifles achieved that position by offering a faster lock time. KDF comes to mind as an example.
The photo's from Whidden of a before and after spring change shows that the faster lock time created smaller groups. It's not about a worn weak spring. Sure, that could be part of it but generally not.

 

Did some miss what wiljen posted? Heavier spring weight is not about hitting the primer harder, it's about lock time. Some of your more accurate rimfire rifles achieved that position by offering a faster lock time. KDF comes to mind as an example.
The photo's from Whidden of a before and after spring change shows that the faster lock time created smaller groups. It's not about a worn weak spring. Sure, that could be part of it but generally not.

Lock time is pretty much irrelevant when shooting from the bench. Even more so when the rifle is clamped in a fixture like it probably is at Whidden's test center. I didn't go back and read the initial post but I don't think they were offering stronger springs. Just new OEM springs

 

When one of my 452s began suffering FTF / light firing pin strikes I disassembled, cleaned and replaced the spring with one from J&P Springs. Said replacement spring stood almost an 1/8th of an inch taller than the old one. That cured the FTFs. As far as shrinking groups? I couldn't tell.