CZ 455 striker re-profile for improved performance

Рет қаралды 8,641

2 жыл бұрын

Пікірлер: 39

@FlowerPowerNZ Жыл бұрын

Thanks for that. As someone new to all of this I really feel like I have learned something from watching your video. My CZ455 strikes in the same spot as yours did but I took for granted this was normal.

@inrangerimfire20two Жыл бұрын

Well, you are very welcome and thanks for the kind words It absolutely is normal for a switch barrel platform, but useless if one is staying with the one caliber. Thanks for the comment

@CHenry1951 2 жыл бұрын

I never thought of doing this, makes sense.................... thanks for sharing !!

@inrangerimfire20two 2 жыл бұрын

Thanks a lot for your feedback. I always appreciate your remarks. Cheers!

@ShooterB1 2 жыл бұрын

I have done this to 3 of my 457's. I have noticed a reduction in flyers and ES seems to be lower. Another thing I just started messing with is bolt shims. They change headspace. Place a .002 to .007 shim behind the bolt pushes the bolt face forward. I just started messing with it. I have shot 3 - 5 shot groups and seems to shoot tighter groups. Just another way to tweak harmonics.

@inrangerimfire20two 2 жыл бұрын

Absolutely correct. The 457 is much easier to shim than the 455 and I too noticed an improvement by tweaking the headspace (especially on a non match chamber) 457 barrel. Thanks for the comment.

@davidlewis3790 2 жыл бұрын

That sounds very interesting, I would definitely be interested in hearing more about the barrel gluing and shimming to adjust headspace. I am wondering where one would get the shim's from, I know Lilja barrels provide some with their barrels. The world of rimfire is a big place and always new ideas and strategies, never boring and a lot of information to learn. Keep up the great work

@inrangerimfire20two 2 жыл бұрын

You can also shim the bolt. This is the direction I went on my last 457. You put the shims in between the two halves of the bolt and the result is the same as barrel shims. I believe I used 3/8ID/5/8OD from Amazon. It is a good idea to buy an assortment of sizes so you can find tune them.

@davidlewis3790 2 жыл бұрын

@@inrangerimfire20two Thanks Dan, just order a shim kit and I will play around with different thickness sizes. I as well order a IBI barrel and it should be here shortly so I'm excited to play around with a new barrel and tuner. How was your IBI barrel and did you have to shim it for better results. Thanks as always, Dave

@inrangerimfire20two 2 жыл бұрын

My last 457 had issues with extraction and ejection with the IBI, so I had to shim the bolt which solved the problem. I measured the tenon on the IBI and it was the same as the CZs factory barrel, but the VPT model at that time did not have a match chamber and as a result there was no issues with such a loose chamber compared to the IBIs super tight one

@carfvallrightsreservedwith6649 8 ай бұрын

So this mod SHOULD benefit other manufacturers rimfire rifles firing pin performance. Your rifle's original strike looks just like strikes I've observed on every rimfire case I've ever looked at.

@kmpdesigns Жыл бұрын

I just did this to my cz457 which had been plagued with extraction problems since i got it. Which was exacerbated by a match grade barrel. I wasn’t able to get through a 10 round mag without several cases getting stuck in the chamber after firing (which had to be pried out of the chamber with a pick). I did the extractor reprofile without any noticeable positive change in extraction reliability. This firing pin mod seems to have solved the problem. I have gone through several mags without any extraction hiccups

@inrangerimfire20two Жыл бұрын

Excellent to hear! The re profiling can help because the case is not overwhelming deformed (by striking needlessly too high) and essentially peening the case into the chamber. I’m glad this helped your issue and one other thing to consider is bolt shimming for extraction issues. I have had to do all of the 457s I have had for this exact reason Thanks a lot for the comment and keep me updated

@kmpdesigns Жыл бұрын

@@inrangerimfire20two I forgot to mention i did bolt shim as well and it didn’t improve anything. I figured I didn’t have anything to loose by modifying the firing pin. I had only seen one post talking about the firing pin mod helping extraction (snipershide).

@inrangerimfire20two Жыл бұрын

@@kmpdesigns interesting. Have you reprofiled the extractor claw itself, - to more of a hook ish shape? I know that’s slightly risky as the parts are hard to get

@kmpdesigns Жыл бұрын

@@inrangerimfire20two yep

@inrangerimfire20two Жыл бұрын

@@kmpdesigns well, you have done all the usual work. Each of my 457s were like this or became like it even with the stock MTR barrel. It is one of the reasons I moved away from an otherwise fantastic package

@outboardfun3353 Жыл бұрын

Did you notice any improvement in group size

@davidlewis3790 2 жыл бұрын

Ever try a before and after with the same lot of ammo to see the difference over a chronograph and if so were there any difference in muzzle velocity, standard deviation or extreme spread ? What type of difference do you see in accuracy in your groups after the reprofiling ? Thanks for the info, I enjoy your channel

@inrangerimfire20two 2 жыл бұрын

Thank your for your comment and interest, I appreciate it. To be totally honest, I have tested it extensively ( like the gluing in of these barrel) before and after, but this was when the 455 was first introduced and due to that particular testing is why I still do it. I have not done any such testing since as I am personally convinced of it’s effectiveness, but perhaps I will for others in the future.

@davidlewis3790 2 жыл бұрын

@@inrangerimfire20two Thanks, I'm planning on doing the same on my CZ 457. I just ordered a new striker so I will have both when I do the modification so can do some comparisons. I want to put that 10 percent stronger striker spring from YoDave in as well and see if there are any differences. Bill Calfee book, The Art of Rimfire Accuracy talks about the importance of correct firing pin location, shape and striking effectiveness and the results on accuracy. Thanks again from another BC rimfire shooter, keep up the great content.

@inrangerimfire20two 2 жыл бұрын

Oh excellent! That is a wonderful book. The 457 is actually easier as you just kinda file in a notch. The 457 firing pin is designed so much differently, but the idea is the same. Can’t wait to hear your results. -Dan

@joesharman9060 Жыл бұрын

Hi, great video! I’m having light strike issues with my CZ457 MTR. I would love to see a video on doing the firing pin of the 457. You mentioned it was easier, how so? I understand the concept as you explained it, and appreciate it very much. Thanks, Joe

@inrangerimfire20two Жыл бұрын

Hey there! Thanks for the kind words and your experience sums up exactly mine with the 457 platform.. I had nothing but issues with each one I had, and although accuracy was excellent, I was plagued with feeding, extraction, ejection, ignition issues throughout

@Chuck_Carolina Жыл бұрын

100% right!

@outboardfun3353 11 ай бұрын

You said you glue in your barrels. I was wondering what do you use glue them in?

@inrangerimfire20two 11 ай бұрын

Yes I do. I used to use Loctite bearing retaining compound, but I have used JB Weld instead for the last few years now. I found some of the tolerances were too large for the Loctite

@carfvallrightsreservedwith6649 8 ай бұрын

Maybe the .22 WMR could see some gains being that its rims are thicker. It's always urked me that target grade / precision quality ammo has never been advertised for this cartridge. "Plinking" and small game is about as far as manufacturers want to promote it, whereas .22LR can / has "match" grade ammo out the ying-yang. But that raises the question as to WHY the .17 HMR is so much more accurate than its parent cartridge (.22WMR). Oooooh, maybe a .20 cal rimfire with 20-35 grain bullet option built off the parent case of the .17WSM (Olin/Winchester .27 caliber nail gun blank) could fill the void between the .17 WSM and the .17 Hornet.......,EEEhhh!, and put a 40° shoulder on it and call it the .20 AIR (Ackley Improved Rimfire)! Wouldn't THAT would be FUN if it worked! Damn, I've got to claim intellectual property now.

@johneperjesi9979 Жыл бұрын

Have you noticed any longevity issues with the firing pins, after the modification?

@inrangerimfire20two Жыл бұрын

Hey there, thanks for the comment. Absolutely none and this rifle sees a few thousand rounds a month- every month.

@xenomorph1317 Жыл бұрын

Funny to see how some individuals seem to get it better then the manufacturer’s itself…… You do know the primer is in the rim itself right?

@inrangerimfire20two Жыл бұрын

Thanks for your interest. This subject has been well documented on CZs due to the switch barrel/caliber system and is a way for an experienced tuner to get the last bit of accuracy out of a rifle that is now a dedicated 22lr. The re-profiling limits the wasted energy of the firing pin strike on the thickest part of the rim and redirects it to the thinner part. If the manufacturer got it so right there would be no need for aftermarket barrels, triggers, chassis, +10% springs, barrel tuners etc. Just sayin’…

@charlesborders2893 Жыл бұрын

WHAT A BOUT GLASS IN BEDDING THE BACK RECOILPAD .

@inrangerimfire20two Жыл бұрын

Im not sure what you mean? My 455 has an Anschutz adjustable butt pad and is full glass and pillar bedded

@charlesborders2893 Жыл бұрын

@@inrangerimfire20two I WAS TALKING ABOUT THE CZ457 -VARM- PRO IT HAS A STEEL BLOCK IN THE REAR THREE QUARTER SQUAR X QUARTER THICK WITH A GROVE ,IT HAS A LITTLE MOVEMENT AND YOU CAN GLASS IT TO ELIMINATE MOVEMENT I WOULD THINK GLASS INBEDING THE RECOILLUGS KEEPS IT FROM MOVEING .