cz 455 giving me fits

[corey4]

to make a long story short, i have a CZ 455 22LR that is giving me fits. when i first got it, it would do 1.5" at 50yds with CCI SV with these random fliers all over the place. i know i know, try different ammo. really the only ammo available local is CCI SV, and i have a good bit of it now.

after about 1500 rounds i still get these random fliers. i have noticed some things thru experimentation. if i pull the rifle into my shoulder with the grip and the butt hook, i'm not talking tight, i'm talking mother fucking it into my shoulder pocket as hard as i can, it will do ok. but after awhile, i start to fatigue and i would say it's not really a NPA and that's not good. also, from different positions, it's not always possible to hold the butt hook. for example, think of those old metal chairs that our grand parents had. they are curved at the top and smooth metal on smooth plastic is pretty slick, so i have to hold the rifle with my support hand. i like to sit or kneel while shooting off one of these.

what i have noticed as well is just touching the rifle near the butt hook will change my POI .5mil. it just depends on where i touch it. no pressure involved, just putting as finger here or there throws the round. it's repeatable as well. for example, and this is a strange one; if i put my finger at the corner of the butt hook and chassis while holding my rear bag, the POI with be .5mil high. if i hold the rifle the same way, but place my finger on the butt hook it self, it will be POA-POI. again, no pressure involved. the other one is while holding the rear bag. if i touch.......just touch the stock with the thumb, the POI will be .5mil left, no pressure involved. hold the rifle the same way, but don't touch the rear end of the stock with my thumb, POA-POI.

so i'm just wondering if anyone has noticed this or run into this.

specs, because people always ask:
CZ455 22lr
20" varmint
threaded for sico sparrow
KRG 180 x-ray with W3 rear end
CCI SV at 1090fps

 

[justin amateur]

Stock flex is my thought. Oversized inletting and slim lines make for a springboard effect.
In order to eliminate the problem off the bench, my bag is set just forward of the magwell.
Set the front support out by the sling stud and the rig slings so many strays you have to call animal control. [IMG2=JSON]{"data-align":"none","data-size":"full","src":"https:\/\/lh3.googleusercontent.com\/R_Hd0dprLsAvsmi2FHlj8I_ewHgbscsfAB_Nl7cXZjWYGuFKTfb7tpXqUw6YQTOArRVphu_2Q3g7PwvATg=w419-h241"}[/IMG2]



Shooting off hand, move your front grip back to minimize the bounce.
The other option is to add a couple epoxy filler shims in the barrel channel.
That stops the bounce and allows use of a bipod off the sling stud.

[IMG2=JSON]{"data-align":"none","data-size":"full","src":"https:\/\/lh3.googleusercontent.com\/Un3MsVW1miOa8YcGN2cdU0nb2hrpedOsOehgYkBFQVzXsvKZjmYM-oC1uVLJoMXGTtpgmXICNQt8ock0Xw=w361-h241"}[/IMG2]

 

[shoot4fun]

I have owned my current CZ455 Tacticool model for a couple of years and ,while I have shot it some, just got serious about making it shoot well enough for a club "sniper" match we have.
The thing I noticed is POI shift in a pattern of 1st shot low at at POA and second shot it moves up several inches. It will usually stay there as long as I want to waste ammo seeing it shoot high. But once I adjust the scope back to desired POI then everything goes smoothly. Me, I didn't really put the blame on the rifle as much as thinking it may the a suppressor gassing thing of a shooter is a dumb ass kinda thing. Either way I gotta figure it out before the next match. May try screwing with action screw torque. A buddy did a test on his and found the torque values it shot best at. BTW, the front and rear came in at different numbers. His stock is Manners and mine is Boyd's so maybe that won't work for me either.
The only other thing I could mention is to check or redo the crown. CZ has been known to not spend a lot of care at that point of the barrel in the past.

 

[45cal4life]

I'm using 45 inch pounds in my Boyds stock that is fully bedded and with 2 pillars

 

[EddieE]

shoot4fun look up http://www.rimfirecentral.com/forums...d.php?t=333628 is this similar to what you are seeing?

 

[kashaV]

I would take out the action screws and check how loose the receiver is in the in-letting. If there is any front to back or side to side play, you will need to bed the stock. Because you are pressed for time, use some aluminum tape in layers between the receiver and wood to make an even but tight fit in both directions. Do this all below the wood level so you don't see any tape. This has helped me under similar circumstances. It is a temporary fix and is a great aid in diagnosing these issues. Check that the barrel to receiver bolts are torqued the same and that the barrel is free floated. Later you might want to bed the entire stock and barrel. Get some allen or torx screws for the receiver so a proper torque wrench can be use.

 

[Kadams1563]

I also think it's a action movement issue. I would think bedding the action would fix it.

PM user djdillon I think that's his name. He is a certified CZ guru.


Sent from my iPhone using Tapatalk

 

[shoot4fun]

shoot4fun look up http://www.rimfirecentral.com/forums...d.php?t=333628 is this similar to what you are seeing?

No, just the opposite. I fire a couple and they both POI at POA. It is usually then that the 3rd and 4th shots jump jump straight up about 1.5-2 MOA. I make a scope correction and then everything is back spot on. I would suspect the scope but it tracks great and the adjustments are true. It has also been verified on another rifle. Barrel is factory barrel with standard (not short leade) chamber.
I'm going to try it without the suppressor and see what happens.

 

[djdilliodon]

this happens more often when running a chassis setup on a rimfire or an unbedded traditional stock. Easy to fix, skim bed the entire action area of the chassis and it should be good to go.

 

[woogie_man]

The KRG stock has little to no flex in the front. I have loaded my bipod excessively and have never had any accuracy issues.

Check that you seated the rifle correctly in the stock. Check barrel retention screws
Check headspace
Check scope

There are many different things it could be. Heck try the original stock and see what happens. Sometimes you just get a bad barrel from the factory.

 

[corey4]

Stock flex is my thought. Oversized inletting and slim lines make for a springboard effect.
In order to eliminate the problem off the bench, my bag is set just forward of the magwell.
Set the front support out by the sling stud and the rig slings so many strays you have to call animal control. [IMG2=JSON]{"data-align":"none","data-size":"full","src":"https:\/\/lh3.googleusercontent.com\/R_Hd0dprLsAvsmi2FHlj8I_ewHgbscsfAB_Nl7cXZjWYGuFKTfb7tpXqUw6YQTOArRVphu_2Q3g7PwvATg=w419-h241"}[/IMG2]






Shooting off hand, move your front grip back to minimize the bounce.
The other option is to add a couple epoxy filler shims in the barrel channel.
That stops the bounce and allows use of a bipod off the sling stud. [IMG2=JSON]{"data-align":"none","data-size":"full","src":"https:\/\/lh3.googleusercontent.com\/Un3MsVW1miOa8YcGN2cdU0nb2hrpedOsOehgYkBFQVzXsvKZjmYM-oC1uVLJoMXGTtpgmXICNQt8ock0Xw=w361-h241"}[/IMG2]

maybe i'll try moving the bipod back as see what happens

shoot4fun, i'll try the unequal action screw values.

eddieE, that doesn't seem to be my problem.

I would take out the action screws and check how loose the receiver is in the in-letting. If there is any front to back or side to side play, you will need to bed the stock. Because you are pressed for time, use some aluminum tape in layers between the receiver and wood to make an even but tight fit in both directions. Do this all below the wood level so you don't see any tape. This has helped me under similar circumstances. It is a temporary fix and is a great aid in diagnosing these issues. Check that the barrel to receiver bolts are torqued the same and that the barrel is free floated. Later you might want to bed the entire stock and barrel. Get some allen or torx screws for the receiver so a proper torque wrench can be use.

there is a ton of play side to side in the chassis. i'll give the AL tape a try. barrel screws are torqued the same and the barrel is free floated. i tried what someone suggested about putting a pressure point at the tip of the stock with some card board. while it did eliminate the barrel moving when i mother fucked it into my shoulder, it still didn't help much with the random fliers. i'll have to try this again.

The KRG stock has little to no flex in the front. I have loaded my bipod excessively and have never had any accuracy issues.

Check that you seated the rifle correctly in the stock. Check barrel retention screws
Check headspace
Check scope

There are many different things it could be. Heck try the original stock and see what happens. Sometimes you just get a bad barrel from the factory.

there is tons of flex in the forend of this stock. i'll have to try and get a video of it. i was showing a buddy that i bitch to all the time about the rifle. i showed him how hard i have to pull the rifle into my shoulder and he said "holy shit look at your barrel move when you do that!". the original stock has gone to another hider. the scope is fine. ive had 3 different scopes on this same BA with the same results; a gen1 viper pst, a gen2 viper pst, and gen2 razor.



also, just to be clear, this rifle did the same same thing with the random fliers when i had the manners T4 on it. but that was when i first had it and didn't try much experimentation i listed in my OP.

 

[corey4]

[IMG2=JSON]{"data-align":"none","data-size":"full","src":"http:\/\/i.imgur.com\/OemVsVn.jpg"}[/IMG2]

here's the rifle in question, it's jsut wearing a gen2 razor right now.

teh whole point of going this route was to match my 308

 

[woogie_man]

Interesting. Are the bolts that hold the forend on tight? Mine has next to zero flex in the front. Will take a look when I get home from work tonight

 

[corey4]

Ok, really really stupid question...

Why would it matter if the forend has some play? The barrel is free floated, even when I put "mother fucker" pressure into my shoulder. And what does that have to do with my rounds going .5mil high or left from just touching the butt end?

 

[BJ343]

mate this is from an Aussie on rimfire central


"I was getting close to crying, throwing things, selling the beautiful rifle etc! I finally talked to the quiet AAA grade shooter that can pull off 50.3 out of 50 targets consistantly with a cold barrel.
His advise was that all the experts believe that 'leading' can never happen in a 22lr and that 22lr's 'never' need cleaning!
He has bought 2 rifles cheaply in the past two years with this problem and fixed both of them
What he says happens is that a fine layer of lead builds up in the throat of the rifling just after the chamber, not seen by naked eye, but he owns a bore scope and can see this.
for the fix, he recommends a nylon brush, filled with jb's bore paste, and a loooong time working back and forth just on that breach area, the part where the rifling meets the bullet! no going from end to end as with the copper brush but just reversing directions and short strokes on that point with the nylon brush after hours of this, dry patch it clean

the nylon wont hurt the barrel the paste will only remove the lead and my initial results speak for themselves

He recommends that if your rifle is touchy as far as cold barrel fliers are concerned that before every important shoot you use the nylon brush and paste and then patch it clean, run 2O or so rounds through it for practice and learn to shoot like him!

A bit more on what he rekons is actually going on, that tiny layer of lead is 'grabbing' the first bullet because the lead is 'set' or hard because the barrel is cold, but once you have fired that first shot that lead becomes malliable, or soft, due to the hight temperatures of the combustion that happened millimeters from it, and therefore its doesnt hinder the next bullets passage, therefore the first shot is WILD and the second close to spot on

 

[redneckbmxer24]

Your ammo is mind fucking you. CCI SV is a good load as far as consistency when compared to other typical ammo on a shelf at a big box store but it doesn't compare to even the lower end match stuff. I always test several match loads in a new rifle and see what it likes best. For me the go to is several varieties of Wolf, RWS, SK, Eley, FGMM and Norma to test. You'll typically find a couple that it really likes and has a good ES/SD. That's where I'd start. I understand it may not be available locally but thats why you place an order for some 50 boxes of a bunch to try, decide what it likes, and order a crap load.

The two samples of CZ's I had would cut .5-.75" groups at 50 yards with match ammo. Even the match ammo it didn't care for was 1" at most and both rifles were completely unbeded, one was a 455 Precision Trainer and the other a 452 American which again tells me you have a ammo problem.

If there is an issue with the gun itself that's contributing to the flyers there's no way of making an accurate assessment without first using quality ammo that it shoots to its potential. Any assessment without first using good ammo is a blind one, and I'd be willing to bet the ammo is 100% of your issue.

 

[metal2meat]

I agree with redneck, it's cheap and sometimes fascinating to see what a change in ammo will do. I bought a 455 varmint last year and was not impressed with the accuracy. I messed with at least seven different brands of ammo and found three that showed promise. I read about running 1000 rounds before expecting things to settle down and had fun doing that with CCI standard.

I did get impatient at times and I bought a Boyd's laminate stock, pillars from eBay, and had it bedded. Right around 1000 rounds it settled in and is shooting great! It shoots great with the CCI, Ely target and Geco auto-something or other. A couple weeks ago I won a local 22 benchrest match shooting off a bipod against guys shooting Annie's, Rem 40's and complete customs on high dollar rests.

Try some different ammo, if that doesn't work, bed it. I also played with the torque of the action screws a bit, but it yielded little results for me. Good luck!

 

[Tucker301]

Got a good heavy vise and a place to firmly anchor it to the bench? Pull the barreled action. Lock it down prom pussy tight in a set of polymer or aluminum jaws and fire some groups. Now we know if it's the rifle or something in the stock, ammo, optics, or shooter.

 

[corey4]

There was a guy today that told me to get a lead sled like him. I like your idea too Tucker.

I tried moving the bipod back, it does take out a lot of the flex in the forend, I also took apart the forend and made sure everything was tight. Forgot to try reducing the barrel torque in the rear screw.

I was having a bad day, so I'm not sure my mind was 100%. I forgot my key card in the wife's car, so had to hunt her down at the mall, then I realized I forgot my damn target stands and targets and had to go home. A 15 minute trip turned into an hour, all without the comfort of my cigarettes (been 2 months)...fuck me running.

The guy with the lead sled was giving me some advice. When he was checking out the bedding area and he tapped the muzzle end with his finger, the barrel looked like a diving board. He suggested bedding an inch or so forward of the receiver.

 

[kl3309]

You've already half-way figured it out. It's the springy, plastic forend on your KRG chassis. I had that chassis briefly and saw that just setting the rifle down on its bipod had the front of stock flex a tenth of an inch or so just from the weight of the gun. I'm seeing that as stored energy that releases into the platform when you fire the shot and at the instant the rifle moves (however slightly) under recoil. The influence of that energy release would vary of course depending on how the rest of the platform is damped (by you) on that particular shot.
I was wanting to have a new forend made out of billet because I liked everything else about the chassis, but then the MPA became available so I got that instead.

 

[woogie_man]

Let us know what you find.

start with tuckers idea and go from there

 

[PAYDIRT]

My 455 slings flyers all over the place. Gets dirty very easy and with a cold barrel it can't hit a 6" plate at 50 yards. It completely left me hanging today in a nrl match, 0 for 4 at a 2 1/2" plate @ 100 and that was prone off a bipod. My nephews Savage MK II will shoot circles around my 455. And now it's looking like the only barrel upgrade is a $450 Lilja.

 

[EddieE]

My 455 slings flyers all over the place. Gets dirty very easy and with a cold barrel it can't hit a 6" plate at 50 yards. It completely left me hanging today in a nrl match, 0 for 4 at a 2 1/2" plate @ 100 and that was prone off a bipod. My nephews Savage MK II will shoot circles around my 455. And now it's looking like the only barrel upgrade is a $450 Lilja.

If you want to stick with the 455, wait for them to offer the 457 barrels with a "match" chamber. I think it should drop in with no issues. Supposedly CZ is going to guarantee 0.6" groups at 50 yards.