New CZ 457 bolt super tight when closing

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DD AT4

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Sorry for the newbie question — I’m new to guns. I just picked up a CZ 457 Varmint MTR and I’m wondering how stiff the bolt is supposed to be when closing it.

From what I’ve read, it sounds like any new bolt action can be a bit stiff when new, but how stiff is too stiff?

Right now, I really have to put quite a bit of force to close the bolt when there’s a round in the chamber (using CCI SV). It feels like a lot of pressure — enough that my hand/fingers would get sore after doing it a few times. When it’s empty, the bolt still feels a little tight but much smoother.

This can't be normal can it?
 
Yes, This is 'common' with VMTRs, and will vary depending on the brand of ammo. These CZs 'mostly' are more compatible with SK/Lapua ammo, from what I've read on Rimfirecentral .com in the CZ sub-forum and other forums. As well as my experience over the past 7-8 years with shooting CZs. My VMTR bolt handle is still 'fairly stiff' with SK 'flavours', even after ca 2500-ish rounds. You might find some brands of other ammo that is less snug, but likely Not as accurate as the SK/Lapua brands. I usually use SK-Magazine ammo for 'fouling', like 10 rounds after a bare-metal cleaning. Then I go to the 'Flavour of the Year' for my supply, which is SK-RM.
There are many opinions on cleaning to metal, but from what I've read most competition shooters go that far, and use 10-or so fouling shots. If you read forums like Accurateshooter, Snipershide, and others you will find varied opinions but predominately for the 'Clean barrel'.
Lots of info out there . . . as they say, watch out for the rabbit hole 😉
PS - Your bolt will get better as you use it But I suggest you try several brands of 'better quality' ammo. CCI-SV is OK for many rifles but a VMTR deserves a better level. I've read that some VMTRs like Eley or Aguila and especially RWS, so those may be brands to try. Better quality will run at least $15/box of 50 . . . And UP ! The problem you're encountering is Mostly due to the inconsistent 'rim thickness' of the CCI and Other Brands. SK/Lapua seem to have a bit better QC overall.
 
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DD AT4 said:
Sorry for the newbie question — I’m new to guns. I just picked up a CZ 457 Varmint MTR and I’m wondering how stiff the bolt is supposed to be when closing it.

From what I’ve read, it sounds like any new bolt action can be a bit stiff when new, but how stiff is too stiff?

Right now, I really have to put quite a bit of force to close the bolt when there’s a round in the chamber (using CCI SV). It feels like a lot of pressure — enough that my hand/fingers would get sore after doing it a few times. When it’s empty, the bolt still feels a little tight but much smoother.

This can't be normal can it?
Click to expand...
If you're concerned buy a set of go no go gauges and check the headspace.
 
DD AT4 said:
Sorry for the newbie question — I’m new to guns. I just picked up a CZ 457 Varmint MTR and I’m wondering how stiff the bolt is supposed to be when closing it.

From what I’ve read, it sounds like any new bolt action can be a bit stiff when new, but how stiff is too stiff?

Right now, I really have to put quite a bit of force to close the bolt when there’s a round in the chamber (using CCI SV). It feels like a lot of pressure — enough that my hand/fingers would get sore after doing it a few times. When it’s empty, the bolt still feels a little tight but much smoother.

This can't be normal can it?
Click to expand...
What ammo are you using ?
I found American Eagle was tight chambering in everyone on my 454's.
Not tight enough to worry about shaving lead from the projectile, but tight for use of a better word.
CCI Stingers even more so.
Talk to the retailer who sold you the gun and see what they may offer or suggest.
Tight Groups,
Rob
 
Short answer: It is not normal.

Is this a brand new rifle or did you get it used?

If new, talk to the store you bought it from and try to get this addressed.

If used, you very well may have the bolt shimmed, and it can be an easy fix.

Let us know if it's new or used.
 
Thanks everyone for the insights!

It's brand new, and I've been using CCI SV. I knew I'd be buying match ammo eventually, but I just figured I'd use some decent, cheaper ammo just to get acquainted with it.

I'll try different ammo when I get a chance, but was just curious how stiff a bolt might be brand new since I'm really cranking it down with force. Practically have to grip the underside of the rifle with my fingers for leverage while pulling down the bolt lever.
 
Definitely try a few different ammo. Start with some eley, as their rim thickness is significantly smaller than for example Lapua/SK. .0039" VS .0042". Not sure about the CCI rim thickness, I never measured that.
Also, a reasonably priced Norma Tac22 works well in my cz, and shoots surprisingly well.
 
DD AT4 said:
From what I’ve read, it sounds like any new bolt action can be a bit stiff when new, but how stiff is too stiff?

Right now, I really have to put quite a bit of force to close the bolt when there’s a round in the chamber (using CCI SV). It feels like a lot of pressure — enough that my hand/fingers would get sore after doing it a few times. When it’s empty, the bolt still feels a little tight but much smoother.

This can't be normal can it?
Click to expand...
Many CZ 457 MTR users report that the bolt is hard to close. It's not that the bolt to receiver fit is too tight. What is happening is that, with the MTR's CZ match chamber that's not as long as the standard CZ chamber, the bolt has to push the bullet into the rifling. This often requires a little more effort.

This can be especially a problem with CCI SV ammo. The problem according to CCI is that the length of the driving band on the CCI bullet is longer than on match ammos. In addition, CCI says, their ammo is designed for SAAMI chambers which are more generous than the CIP chamber specs used by CZ. The more generous chambers allow for all kinds of .22LR ammo to be used, including Stingers, which have longer than usual casings. (For more on this see the CCI information in post #4 here https://www.rimfirecentral.com/thre...lhouette.333135/?post_id=2865358#post-2865358 )

Another consideration is that with a new rifle with very little use, it has not yet experienced any of the slight "wearing in" that will usually occur as a rifle sees more use.

For a look at discussions in Rimfire Central relating to the issue at hand see the following among the many there
https://www.rimfirecentral.com/threads/hard-to-close-bolt-on-new-cz457-mtr.1315993/
https://www.rimfirecentral.com/threads/cz-457-mtr-tight-bolt.1316426/
https://www.rimfirecentral.com/threads/cz-457-mtr-hard-cartridge-chambering-question.1304318/
 
there js a bolt lubricant we be chrest shooters use sold by some retailers

the importer is on Lethbridge cannot but think it is plenty o patches if it is ok to post that

try it it works and smooths up the bolt TREMENDOUSLY

works better on centerfire but also rimfire if U CLEAN THE DARN BOLT FIRST


25 bucks shipped the product is probably 17 bucks

U will thank me later
 
". . . Practically have to grip the underside of the rifle with my fingers for leverage while pulling down the bolt lever."
Yes, You WILL have to "Hold" the rifle . . . if you have rifles that don't need that they must have sloppy bolt retention IMO.
As Grauhanen says, the VMTR chamber is 'snug' and you will have to drive the bullet INTO the rifling to some degree, for Most ammo brands.
As for bolt lube and lube in general, 'most rifles' benefit from very light lube only on 'friction surfaces'. I use Permatex Synthetic PTFE Grease ( CT @ $16 in auto section) and only put a TINY BIT (matchhead size) and spread it Very thinly. This grease is viable down to like -30C or so, and will NOT "melt off" either.
 
As mentioned in Reply #8 previous, the CCI SV 'driving band' on the bullet is probably your problem. Try a different bullet shape with less/no band. As mentioned in Reply #4, CCI Stingers will also give you a chambering workout . . . . because the brass casing is longer than most other LR rounds.
 

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I had the same issue when I installed a CZUB Varmint Barrel on my .455 Super Match. It was tight to the point I was not comfortable trying to close the bolt.

It was a head-space issue, here is how I detected it: Using a dial caliper, I checked the rim thickness on unfired loads (CCI STD, Norma Tac-22, and Elie Match), I measured the rim thickness, then I chambered all three and remeasured. They were all thinner after the bolt being forced closed on them. I ended up adding about 0.0015 shim to the barrel tenon. Closing force is now only slightly tighter than dry cycling, and accuracy is amazing. Originally I made a shim out of a Polish Beer can, but since had a fellow member send me some un-used barrel shims.

I love my rifle.
 

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Cycle the bolt on an empty chamber... easy or hard?

If easy, then the ammo you are using is too tight (thick rim) for the current headspace. This is NOT ideal and will not get better with time. Eley likely has the thinnest rims but measure to be sure. Also, check that the extractor is not f'ing up somehow.

Note rim thickness on ammo can vary... and lower QC ammo can vary more. Try some other quality match ammo to identify where the issues might be

If hard on an empty chamber, then look for burrs or anything getting in the way.

With proper headspace for any given ammo, there will be a very slight gap between the bolt face and the rear of the ammo. Contact or worst, crushing the rim is not ideal. Maybe a gunsmith or headspace gauges are in order?

YMMV
Jerry
 
Thanks again for everyone's thoughts and ideas, this is such an amazing community!

I'm going to try some different brand ammo as everyone has suggested, and work my way through there. Even though I thought I scoured all the message boards, I'm finding more and more and more posts about the same thing now all of a sudden, grauhanen, thanks for the links!

When cycling the bolt without ammo it feels easy, but with ammo is when it's hard to close it. One thing I did notice was with the CCI SV, some felt easier to close than others, so it seems to line up with ammo consistency being the culprit.

Just wanted to make sure I wasn't causing damage, but if tight ammo is the case, should I stop using this ammo altogether?
 
Mysticprecision said:
Cycle the bolt on an empty chamber... easy or hard?

If easy, then the ammo you are using is too tight (thick rim) for the current headspace. This is NOT ideal and will not get better with time. Eley likely has the thinnest rims but measure to be sure. Also, check that the extractor is not f'ing up somehow.

Note rim thickness on ammo can vary... and lower QC ammo can vary more. Try some other quality match ammo to identify where the issues might be

If hard on an empty chamber, then look for burrs or anything getting in the way.

With proper headspace for any given ammo, there will be a very slight gap between the bolt face and the rear of the ammo. Contact or worst, crushing the rim is not ideal. Maybe a gunsmith or headspace gauges are in order?

YMMV
Jerry
Click to expand...
Check the easy stuff first; while any of the reasons you posted could possibly cause the tight bolt, ALL of the similar issues on RF Central were the result of tolerance stack up between the receiver and the barrel tenon length, and were easily diagnosed, without buying mor one time use stuff like headspace gauges, which the average person may not have the expertise to use properly anyway. (kind of like bore gauges, they are really cool, but almost no one seems to know what they are looking at; finding issues that don't even exist).

You don't have to read too many CZ forums to note that since the 457 was introduced, quality control as slipped a bit. This is likely due to the demand for these rifles out stripping their ability to produce them. Process engineers look for ways to increase productivity by streamlining production to reduce cycle time per item. Speaking from experience in Automotive, sometimes unexpected issues arise showing weakness in the process.

Check the rim thickness before and after fully chambering at least three rounds. if they are thinner after than they were before, then order a shim kit. If no difference is detected, then start looking for other issues.
 
DD AT4 said:
Thanks again for everyone's thoughts and ideas, this is such an amazing community!

I'm going to try some different brand ammo as everyone has suggested, and work my way through there. Even though I thought I scoured all the message boards, I'm finding more and more and more posts about the same thing now all of a sudden, grauhanen, thanks for the links!

When cycling the bolt without ammo it feels easy, but with ammo is when it's hard to close it. One thing I did notice was with the CCI SV, some felt easier to close than others, so it seems to line up with ammo consistency being the culprit.

Just wanted to make sure I wasn't causing damage, but if tight ammo is the case, should I stop using this ammo altogether?
Click to expand...
Try more ammo, I think you have already answered you own question; barrel shims are likely the answer.
 
Unless headspace is incorrect from the factory, the problem remains as described earlier.

Before looking at shims, check the headspace to confirm that it's good. Use a headspace gauge such as a Go gauge.

l_184000051_1_l.jpg
 
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"Damage" is the wear on the bolt/receiver due to extra pressure. Not immediate, but why not avoid it.
Hirsch has some SK/Lapua - some SK Mag is good 'basic', then 'crack the wallet' 😄 They also have some Eley to try, some CZs like it better. get a bunch but remember the cost of shipping adds up. Not a lot of choices in Can this time of year.
https://www.hirschprecision.com/index.php?main_page=index&cPath=105
 
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