CZ 457 Bolt Shims - trigger shims - do they actually work?

CZ 457 Bolt Shims - trigger shims - do they actually work?
In this video we test Trigger Shim shim kits for the CZ 457 LRP to see if we can extract more accuracy playing with head space. Starting with a factory rifle shooting a few groups to get a baseline. when our baseline groups have been fired we start testing the shims in order from thinnest to thickest. with the thinnest shim installed we fire a couple more 5 shot groups then move to the next thickness of shim and so on. Get comfortable crack a beer and stay tuned because you are watching Browned on KZbin!
This is a CZ 457 review and Trigger Shim test
Rifle setup: Timney trigger, amazon arca rail custom fit, Valquartsen exact edge extractor one side only, Bipod Factory Carbon Fiber 6-9" swivel BIPOD, Discovery Optics ED PRS 5-25 gen 2, IBI Barrel
Hope you enjoy the testing and DON'T FORGET TO SUBSCRIBE! , COMMENT, AND LIKE! the video.
There will be new videos releasing every Sunday morning at 9 am!
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parts used: Timney trigger, amazon arca rail custom fit, Volquartsen exact edge extractors, Bipod Factory Carbon Fiber BIPOD, Discovery Optics ED PRS 5-25 gen 2, IBI Barrel
Hope you enjoy the testing and DON'T FORGET TO SUBSCRIBE! , COMMENT, AND LIKE! the video.
There will be new videos releasing every Sunday morning at 9 am!

[@22rimfireultra67]

Very nice planned out video test! Enjoyable and informative to watch! The camera images of the target were good enough for me to measure and calculate averages for the groups (keeping in mind the measurements are not as exact as would be if target were in hand, but the measured results still offer insight). The pertinent groups are the factory group and the 0.015 bolt shim groups. The rest were significant enough to be excluded out right. Groups measured CTC. Factory 3 groups: 0.89", 0.58", 0.50". Average= 0.65". Shim 0.015 Groups x 3: 0.42", 0.41", 0.71". Average=0.51". F/U Shim 0.015 Groups x 4: 0.38", 0.46", 0.43", 0.54". Average=0.45" Cumulative Shim 0.015 Groups x 7: Average=0.47" That is a Whopping 💥 38% difference between factory and 0.015 bolt shim. A consistent level of performance improvement with a known good medium grade ammunition. It would have been nice to have had 4 more groups from factory set up, however, historically from my experience, the results of the 3 factory groups presented seem typical for a good day out with same or similar set up and ammunition. This should translate to improved accuracy on target bulls as well. Great video................thanks!🙂

[@BROTUNED]

Thanks for doing the calculations really appreciate that. I really should have done it and included it in the video. Now for next time I’ll make sure I do it.

[@22rimfireultra67]

@@BROTUNED Oh, I enjoyed doing 🤓it pretty much !

[@johnstewart2011]

“One accurate measurement is worth a thousand expert opinions.” Once again you do a better job with your tests than most KZbinrs.

[@martin2514]

Make sure you put a bit of oil on the shims. You can extend the life by a lot. I make these in the UK. Depending on the material the shims are made of can affect the life of them. They are designed to be stacked. Oiling them extends the life a lot. I make them for the CZ457, CZ 455, 452 and Brno as well as the anschutzs match 54 action.

[@BROTUNED]

Thanks for sharing this

[@andyturner2693]

Where in the UK can I buy your bolt shim kit please?

[@foonus406]

Wonder why your groups are opening up as you move down the target? I bet if you put a piece of plywood shim under your bag instead of pinching up on it to hit those lower targets they would look a lot closer to the ones on top. My 455 has a pretty stiff bolt close with the SK ammo, but it does shoot really well. When benchrest shooters shoot .22 they clean the barrel as often as possible, I am convinced there is a reason for that. I would try to clean the barrel with the swap of each shim, take 5 foulers on the bottom target, and move up the line to see the groups with the barrel in the same state - there were over 100 rounds between the first and last groups. Running a chronograph while testing isn't a bad idea either, as you can see easlily if there was a notable FPS difference in any "flyers" . Thanks for the video!

[@BROTUNED]

Great point I may have to revisit this

[@misterlewgee8874]

Getting statistically significant result from shooting groups apparently takes alot of shots...re hornady podcast groups size...

[@dougkrogh4262]

Good review 👍

[@donniepowell7146]

Amazes me that one and half thousands makes such a difference.

[@douglassnyder1292]

Thanks for making this. Nicely put together. I am about to do this exact same thing with my CZ 455. This is helpful to see. Blows my mind how you can shoot a group like the top one in the .003 column, and then move down 3" and then shoot a group below it and it opens up like that. I can never figure that out.

[@BROTUNED]

Part of the funny 22lr quirks

[@JohnSmith-jh1iy]

I was thinking to myself “damn that guy is quick cycling the bolt!” Then i realised it was sped up 😂

[@BROTUNED]

Ya ha ha it would have been a very long video if I didn’t speed up the shooting part. But yeah almost as fast as a semi

[@daviddudley5895]

Thanks for the video. I have done quite a few 50 shot groups and found things all seem to even out and look about the same. For me I decided to buy as many of the same lots as I can afford and practice in the wind. Reading the wind wins the matches.

[@905orange]

You can quickly determine the proper shim my using a small piece of plasitgage on the back of a cartridge. It saves time compared to taking everything apart and measuring with a depth micrometer or swapping out multiple shims. I have found that getting headspace as close to 0 without crushing the rim to offer the best results.

[@lanceshively2110]

Great Video My Friend, Thank You for using TriggerShims Brand Products! 🙂

[@BROTUNED]

No problem what’s so ever! They definitely get my seal of approval. Cheers sir! 🍺

[@dttrandom]

Thanks for this vid. I've seen other vids of CZ 457 with shims installed but they were done by measuring head space and such and doing a bit of math to determine which shim to use. This one you did by actually testing all the shims. I've bought the shims but have yet to install any. I planned on doing them by measuring head space and doing the math since it's the least amount of work and doesn't use up as much ammo, but I keep thinking that with my slight OCD that I won't be able to resist testing all the shims like you just did.

[@paddywoolley6035]

I did the measure and maths now you got me thinking about doing this too, I know my Army lads aint good with maths either

[@PursuitofAccuracy]

Just messed with some shims in the b14r and had some interesting results. I ran a kind of inverse test to yours where i shimmed the best feeling headspace and tested it across the ammo i had shot in the baseline.

[@fredshebester-wg4vb]

That 0.015 is shooting lights out. Thanks for these videos. You are saving me alot of money, by trying things first.😊

[@BROTUNED]

My pleasure have a great day!

[@johnterhark6516]

Great testing video. 3 thousands shim worked the best on my MTR.

[@BROTUNED]

The .003” was very good in mine also

[@wadesaunders583]

Was your mtr already stiff? Mine closes very tightly...I don't think I could add a shim!

[@vincebelmonte7710]

Wow great just ordred and received two sets for my CZ's your vid surly came in at the wright time thanks BRO

[@BROTUNED]

Glad I could help cheers and enjoy

[@pitts3219]

Most CZ’s headspace are factory set at .46 and .43 is ideal for SK.

[@7come11two]

I tried these in my 457, and I couldn't tell they made any difference at all.

[@pevelyhomeowner327]

Great information! Thanks for sharing. I’ve only shimmed until resistance felt “enough”. I may try this method on my next bolt. 👍👍🙏

[@BROTUNED]

I found the best accuracy for me was when I started to feel the tension but not so mad it would hold the bolt from closing

[@Jdelta22nc]

Thank you for taking the time and ammo to make this video. Now we know what to expect.🥥🥥

[@audieladd2476]

Match Winning Rifle Shim Installation Method. Stack all the shims and drive the bolt in with a copper mallet. Do not use a metal hammer as it may damage the bolt.

[@BROTUNED]

lol

[@audieladd2476]

@@BROTUNED 🤣

[@Dayattherange]

Nice way to test and be absolutely sure, When I installed mine I did it based on headspace and closing of the bolt though I ended up with much the same result. You sort of want the bolt snug not TIGHT. Just trying to get the most consistent headspace possible as rim thickness on 22lr can vary even in high dollar ammo.

[@BROTUNED]

With the.005” shim bolt close was stressed for sure. .0015” was almost as easy as factory

[@joewhite4081]

The sense behind the shims is to only take the slack out of your rifles bolt close you don't want it to stiff you don't want to sloppy that would be the reason the first shim worked well for your rifle a heavily worn rifle would really prefer the thicker shims

[@jgs3647]

appreciate the time and effort involved with this test top man.

[@BROTUNED]

Thanks so much

[@Jeff-mv4yy]

Nice demo , if not too much trouble , it would be great to see back to back with some premium ammo the rifle loves . Thanks for showing . I’m always afraod to take my bolt apart . I stretched the extractor spring once and rifle quit extracting . I had to order from Lithuania and paid a kings ransom . Nowhere in NA had a replacement

[@BROTUNED]

Ya I can do something like that for sure

[@joea4998]

Great test I may need to give this a try. Looks like it tightened it up quite a bit. Thanks

[@esoxecosse66]

Nice one Ryan, got the shims ages ago but haven't tried them yet so you've prompted me to get the finger out and give them a go 👍

[@BROTUNED]

Go for it! Let me know how you make out

[@misterlewgee8874]

I enjoyed Thank you A factory 10 shot group may have been the same as the 1.5 thou ten shot group... The 1.5 thou did look promising. A smaller aiming point may also help...also..for test..maybe keep the point of impact away from point of aim so impacts don't damage your aiming mark. ... Well done though. Would like to see a follow up with factory vs 1.5 thou and maybe another shim. 20 shot groups?..or a larger sample... Mean radius comes to mind too...and possible fliers due to velocity... A great start.

[@mus1970]

Nice effort, thank you for your time, patience, and energy. I'm wondering though, with different ammo (for example Eley, which usually has thicker rims) would you need to repeat the test and perhaps end up with a different shim/no shim?

[@BROTUNED]

I’m guessing that it would be like a tuner and some ammunition would prefer different head space settings

[@markthibault8579]

Interesting test on something I was curious about with my own 457. I have yet to find some match ammo consistent enough in my MTR to warrent going the extra distance to try shims.

[@takedeadaim8671]

Did you do any measuring to determine actual headspace on the rifle? Testing against a known rim thickness (go gauge) so you know how tight your actually getting, can shed some light on the on paper results.

[@BROTUNED]

O I just figured I’d do blind science and just see if there is a difference

[@plinkspot8750]

Man, chasing .22lr groups is a very, very deep rabbit hole. Nothing ever feels "perfect"

[@BROTUNED]

Yes that’s for sure 👍🏻

[@danfromga9696]

One thing consistent about rimfire is that it's inconsistent

[@CountryRimfire]

Wow that is crazy 🤪 Nice video Ryan! Now I want to try this 😮

[@BROTUNED]

It’s a great way to get a little more from a great rifle at a low price

[@rustynut1967]

Great video! I'm going to order some shims so I can hopefully give my buddys Bergara a challenge. We're close but he is a little more consistent and just a tad tighter groups. 😊

[@BROTUNED]

You can do it! Cheers

[@rustynut1967]

@@BROTUNED 😁 I just got done putting in a .0015" shim and did the firing pin mod. We'll see.

[@donaldhanger9807]

Great shooting II may need to get some. Shims!

[@HSmith-uk9hl]

Second target with the .005" shim has only three shots on it. Your last two shots were in the second target with the .004" shim. IOW, you have seven shots in the second .004" shim target and only three in the second .005" shim target. But no matter your best results seem to have been with the .015" shim.

[@zdenkoplese665]

Good job. Good results.

[@BROTUNED]

Thank you! Cheers!

[@gushlergushler]

That was really instructional.... I now need to check where I in Europe I can order shims from.

[@BROTUNED]

I’m sure you can order them from triggershims.com

[@gushlergushler]

@@BROTUNED Just did actually :D they ought to give you a kickback if they notice a surge of new customers now lol

[@BROTUNED]

That would be nice ha ha but basically I pay for all my stuff I don’t get much help since I live in Canada. No one hooks me up. That’s fine I’d be doing to same regardless. Cheers and enjoy

[@gushlergushler]

@@BROTUNED I appreciate your work even more then. Cheers and good shooting.

[@BROTUNED]

Thank you I appreciate that

[@fourty-sevenkick2398]

Nice work, informative, solid!

[@BROTUNED]

Much appreciated! Thanks

[@johngarrett6256]

I think you will like it more at 100 and 200 shoots real nice.👍😀

[@JuicyJust180]

Thank you for this one!

[@BROTUNED]

My pleasure!

[@drewhunt8038]

Good video fellow Canadian!

[@BROTUNED]

Thanks cheers! 🍻

[@ericf4779]

Great video on adjusting headspace with shims. I normally measure first and use barrel shims on my CZ 457's, but bolt shims work, as well. I try to get to .041 for SK ammo. What are your action screw torque settings? Just curious.

[@BROTUNED]

I use 32”/lbs action screws and 35”/lbs for the barrel

[@wayneschenk5512]

Doesn’t this gun come with a match chamber would shims make a difference.

[@BROTUNED]

It does have a match chamber from factory and I tightened up the head space just a bit and it seems to like that

[@FC64002]

I would leave it alone right there

[@audieladd2476]

Anschutz's don't need shims, they come tuned from the factory. Like bacon, everything is better with an Anschutz.

[@sherryengrav3370]

Be sure agrees the shim so it doesn’t wear the bolt

[@richarddesimone4451]

How can you do any quality testing with less than lot tested match ammunition? Then sometime you say "it was me". But then others go out of the group and you say nothing??

[@BROTUNED]

If I say it was me I broke the shot off my aim point. But if I feel I broke the shot and the aim point was where I wanted it I don’t say anything. SK standard plus shoots moa from my rifle and it’s my go to plinking ammo so I figured it would be the best ammo for me to test with since it’s what I shoot 99% of the time. I test everything I can get my hands on for KZbin but when I’m playing around off camera it’s 99% of the time SK standard plus.

[@richarddesimone4451]

@@BROTUNED that's just it! Its "plinking" ammo, not testing ammo. I appreciate the work you do on the video's, but it's not valid results, in this case, for the shims. If you were just testing one brand against others, that's valid..or say different lots against each other, but to test plink ingredients ammo against varying shim thickness? I don't think so!

[@davegrimshaw7318]

Plinking ammo is best to test, if you can tighten up a cheap ammo, save loads of money down the line..

[@richardfisher3656]

Where you buy the bolt shims ??

[@BROTUNED]

I believe the site is triggershims.com

[@Mr.Spectaculous]

I like the content. Watching on the big screen TV. I'm nobody in rimfire but do shoot a lot. I think I'm seeing something in your shooting that I also see in mine. You seem to have a preference for an area on the paper that produces the best group. You didn't measure them but from my couch it looks like the best groups came at the top of the targets. Larger groups towards the bottom. The 457 receiver is capable of flexing. I'm not sure I'd want it too tight to close. Plus not to mention the position upset you might be experiencing with the increased effort. Hard to tell from the TV. If you are ever in Florida look me up. I'll take you inshore fishing.

[@BROTUNED]

Thanks I’d appreciate that

[@douggiek9]

Where can you get the shims from? Thank you

[@BROTUNED]

triggershims.com is where I got mine