Poor accuracy CZ 452 American

[sideoiler]

Recently bought a CZ 452 from a collector never fired , installed a Leupold Vari lll 1.5 x 5 with steel rings some CCI SV. ammo. Shot several 25 yard targets and my best group was one and a half inch five shot groups . Bench fired with bags front and rear. What a dissapointment . Fired about 100 rounds , nothing better than 1 1/2 in. groups , scope seemed ok , brushed and patched bore with G96 . Chamber seemed. Ok , loaded and ejected easy. Cannot understand the poor groups , was fully expecting dime size groupings . Receiver torqued 25 in. Lbs. Hopefully I can get some advise with finding out what is causing this poor accuracy. I only tried the CCI ammo, better quality match rifle ammo might improve the accuracy but you would think CCI. SV could do better.

thanks for any help

 

[natdscott]

Way too many variables for an internet forum to answer with any clarity or accuracy.

Mounts, rings, trigger, mainspring, pin, scope, shooter, barrel, chamber, ammo, rests,..........

 

[EddieE]

at 25 yards, I would expect tiny holes too. That is the worse shooting 452 I have heard of.

try better ammo and if it doesn't improve, come back with an update.

Your groups are grossly oversized. Whatever it is, its not a subtle thing. How is the crown?

 

[*rim-star*]

I would look at the chamber and bore with a bore scope first thing, some CZ's as well as other brands have smeared lands at the beginning of the rifling ahead of the chamber, this problem seems more prevalent in 452's as members over at RFC complained of this and I think CZ listened, doesnt seem to be as bad in later model 455s and 457s, this causes severe accuracy problems if its bad enough, there could be many other reasons as well, good luck with it.

 

[Appalachian]

What did the test target look like?

 

[Tomiboy]

If he never shot it maybe it needs a good barrel cleaning. It may have the gunk in it from the factory

 

[sideoiler]

Hey, thanks for the interest and suggestions , the Leupold scope was the bad guy. Tried amother scope and voila , 5 shots in a very small hole . A good day at the range . Excellant groupings , nice rifle. Trigger needs attention , dang , another project !

 

[AGrizz]

Hey, thanks for the interest and suggestions , the Leupold scope was the bad guy. Tried amother scope and voila , 5 shots in a very small hole . A good day at the range . Excellant groupings , nice rifle. Trigger needs attention , dang , another project !

Take a little look here for your trigger issues.

Diversified Innovative Products - Products

 

[AGrizz]

The ammunition may be something like Lapua Center X, SK Biathlon Sport or SK Standard Plus. Get away from the cheap garbage and the rifle will very likely shoot.

Look here, https://goodshootinginc.com/rimfire-ammuntion/, here https://www.creedmoorsports.com/category/rimfire-ammunition

If this does not do it then you need a bore scope and check the chamber for burrs and the muzzle for a good crown.

 

[Steve@]

Recently bought a CZ 452 from a collector never fired , installed a Leupold Vari lll 1.5 x 5 with steel rings some CCI SV. ammo. Shot several 25 yard targets and my best group was one and a half inch five shot groups . Bench fired with bags front and rear. What a dissapointment . Fired about 100 rounds , nothing better than 1 1/2 in. groups , scope seemed ok , brushed and patched bore with G96 . Chamber seemed. Ok , loaded and ejected easy. Cannot understand the poor groups , was fully expecting dime size groupings . Receiver torqued 25 in. Lbs. Hopefully I can get some advise with finding out what is causing this poor accuracy. I only tried the CCI ammo, better quality match rifle ammo might improve the accuracy but you would think CCI. SV could do better.

thanks for any help

I know this is an old post but wanted to share what I have had to deal with...the 452 I have shot great .. for a while.. then the groups opened up.. have tried all ammo.. all ammo.. was making me crazy.. what happened to my fav .22.... then as the old saying goes.. bought a bore scope .. and found what I believe to be the problem.. Not all barrels are cut the same.. some times.. its not the ammo or the shooter.. but the tube.. dont go crazy.. buy a bore scope or take it to a gun smith that will give ya the time of day .. to find the real problem.. I liked my CZ 452 till it went bad.. Dont allways blame yourself.. get it checked out..

 

[sparkyv]

What'd you find?

what happened to my fav .22.... then as the old saying goes.. bought a bore scope .. and found what I believe to be the problem..

 

[Steve@]

All rifling.. has bad smear at the start of the rifling, at chamber... Not even on all.. some worse that others.. Very ugly..

 

[Steve@]

This tube is very much the picture of your worst nightmare... looks like it was finished with a dull rock.. don't know that CZ will do, if anything, since 452 has been out of production.. only just got the lyman borescope.. no kiddin.. was just to see why this gun just quite shooting.. went from wow to nightmare.. could not figure why.. tried everything.. borecam was only thing left.. and surprise.. I think i found the problem.. Now what? I guess I now have a junk CZ 452.. It Happens..

 

[Scrumbag]

Hi would try different ammo before anything else.

 

[Steve@]

 

[justin amateur]

No...mass produced barrels don't allow the use of the chamber reamers after they're worn out.

Never happen, the techs know better...can't happen....or so I've been told. Riiiiiggghhht.

 

[sparkyv]

From your borescope images, I'm cringing...however, I'm at a loss to connect the reaming images with the rifle shooting well to no longer shooting well.

 

[JBoomhauer]

The above looks nearly identical to my 452. But the thing shoots. Like as good as my vudoo good.

 

[Steve@]

So none of my other rifles have this style of rifling.. so just a guess..

 

[JBoomhauer]

If by style you mean Eastern European shove her in dull and dry, then yes it is unique.

 

[Steve@]

I believe the loss of accuracy is due to the decline of the rifling. In some of the pictures it appears cracks are developing in the rifling and looks like some of the smear has broken off.. can see shadow where the smeared rifling looks like its missing. My best guess. Its circling the drain getting worse from wear. have shot just about 30 different brands / loads of .22 ammo.. all kinds.. some of the stuff that shot well in the beginning no longer can.. which was making me crazy.. In the end nothing seems to shoot well.. went from one ragged hole groups to 1 inch groups with fliers.. @ 50 yards.. very sad..

 

[n2ishun]

Somebody used one of those chamber swages in a drill.
Obvious as all hell.

Who can't see the clockwise turn of the swage in those pics ?

 

[Steve@]

Agree and I dont know the magnification of the borecam , but it sure makes it look ugly I dont clean with a drill only push breech to muzzle wire brush and patch.. So got any idea how I got this mess Q.C. maybe no..

 

[Steve@]

The above looks nearly identical to my 452. But the thing shoots. Like as good as my vudoo good.

Ah Yes.. Mine shoot so nice new it made me look good, I cant say for certain that any one thing made it go bad, But one day I started scratching my head , wondering what went wrong.. I am now bald.. Yes it shot very good until it did no more.. Am still thinking of ways to fix this.. cause.. I sure cant hurt it.. A new project as I see it.. or maybe a new gun.. did someone say vudoo?

 

[JBoomhauer]

All i can come up with it break off the rest of those hangers and see if the accuracy comes back.

Can’t get any worse right?

Have the card on standby .

 

[Im2bent]

So it was shooting good then suddenly its not? I doubt the rifling suddenly smeared it was probably always like that. Maybe your scope took a shit. Try another scope.

 

[JBoomhauer]

Joking aside,

Yours looks clean, but my 452s accuracy would take a dump and the bolt would get hard to close when too dirty.

It would come right back after a good cleaning.

 

[Steve@]

So it was shooting good then suddenly its not? I doubt the rifling suddenly smeared it was probably always like that. Maybe your scope took a shit. Try another scope.

Ya tried that.. It wasn't like one day bad .. it was more like not as good today, cant find anything, check action screw torque, check clean barrel, check another ammo that used to shoot, and after you check everything.. again.. I started the post as something that I had tried everything and could not reason what went bad.. so i looked into the borescope and found ugly rifling.. which I believe to be getting progressively worse. As one of those things you cant normally see going bad but makes you think you did something wrong or overlooked and has you going crazy.. Yes I am now crazy..

 

[Steve@]

Joking aside,

Yours looks clean, but my 452s accuracy would take a dump and the bolt would get hard to close when too dirty.

It would come right back after a good cleaning.

Yes I do believe in a good clean gun cause when i feel it getting gritty.. Oh wait ..its never gritty.. I have been accused of wasting money on cleaning stuff they say I try to much.. How do you know if you dont try..? But come hunting season they wanna see what i have this year. I give them what I had last year..
So thank you and yes its clean and smells like hoppes 9 because I grew up on that stuff.

 

[Steve@]

take the pressure pointing and any other mods out. Make sure the action is tight. Now try a different scope and make sure it is mounted properly.
I had a CZ 452 in .22 that started doing just what happened to you. The scope went bad. Believe it or not, sometimes scopes spoil. CZ's usually don't.

I, at this point, am willing to try anything..again.. Have the gun completely torn down.. again.. So will be building it back up from scratch with some new glass.. again.. Was looking for some advise I had not tried and will gladly take any and all advise one more time before this .22 becomes a safe queen. Have never had a gun go so bad.. I guess that's what is driving me to fix it.. Gotta know why..

 

[Steve@]

Had no idea how common this rifling smear problem is. Didn't know what I was dealing with until I got the borecam. So after reading and reading seems some folks have had success with slugging the barrel to remove the smear.. Looks like I have a new project for the summer.. Will let ya know.. How do you slug a barrel..? Or do you just slug the chamber..? JBoomhauer .. " break off the rest of those hangers ".. You are on to it..

 

[Manning5R]

My 452 has smears, but not like that. My 457 looks perfect. They shoot about the same.....

 

[Scrumbag]

Try a really aggressive brushing and a spear jag with a harsh solvent. See what you can knock off.

 

[Steve@]

Try a really aggressive brushing and a spear jag with a harsh solvent. See what you can knock off.

So that's what I did.. Very aggressive chamber scrub with J-B paste on a patch that was on a .17 brush and really went to town.. new patch, new paste.. several times over about an hour.. Got to my buddy's range over the weekend.. and.. Wolf match target, 5 shot group, 1 ragged hole @ 40 yards, two times, before the rain showed up.. I guess cleaning wasn't good enough, Had to abusively scrub the chamber.. did not knock off any of the rifling smear but its very shiny and smooth. Happy, happy, happy..

 

[Scrumbag]

So that's what I did.. Very aggressive chamber scrub with J-B paste on a patch that was on a .17 brush and really went to town.. new patch, new paste.. several times over about an hour.. Got to my buddy's range over the weekend.. and.. Wolf match target, 5 shot group, 1 ragged hole @ 40 yards, two times, before the rain showed up.. I guess cleaning wasn't good enough, Had to abusively scrub the chamber.. did not knock off any of the rifling smear but its very shiny and smooth. Happy, happy, happy..

Glad it worked for you. Soft lead and baked on lubricant can be a bugger to shift.

Let us know if really settles. I would also recommend some RWS ammo.

 

[Grey Kiwi]

After reading this thread I went to my CZ457 varmint.
Only ~100 rounds through it (SK Match). I have previously 'cleaned' it with Hoppes No9 as that was my normal routine with my CF rifles.
So I dry patched the barrel, then used my newly bought BoreTech C4 carbon remover. First soaked the chamber area for 10 minutes then pushed the wet patch through.
'Good grief Charlie Brown'...I had gunk, and more gunk. Black, nasty carbon residue for the next 3 patches.
Then it came clear (and hopefully clean).
Dry patched and then set it up with Hoppes No9 again overnight.
Will check it later today and lightly oil the barrel then.
Anyway, thanks to reading on here I now know about that sneaky carbon, and I now have the tools to remove it.
I don't have a bore scope, but eyeballing the bore it looks great...shiny as chrome plating down through there.
Will buy a bore scope (Teslong?) sooner rather than later though.
Thanks guys.