Got a couple questions, CZ isn't grouping like it should..

[BenY 2013]

So I'll start off by saying that I KNOW the CZ 455 VPT is capable of shooting good groups, like in the .2 and .3's. It shot this well with the barrel cut to 16.5" and the action bedded and the action screws at 24 on the front and 28 on the back and the trigger tuned to no creep and around 1.5lbs. My barrel set screws are at 32lbs. It shot great and I was happy! All that was needed was final painting.

So I disassembled it all and Cerakoted the barreled action, base and scope rings. I had plugs in both the chamber and muzzle, and every thing seemed to go well.

So today after it has all been reassembled and screws torqued down to the same as before same ammo as well only with a different scope, SWFA 12x. It won't group at all... it's shooting mainly .5 to .75+....

I just can't figure it out. Would the Cerakote on the action affect the torque settings that much? Would it need to be higher or lower torque settings? Are any of my torque settings wrong? I don't think it would be the scope but I have been wrong before for certain! Is there anything that I am not checking?

I appreciate it very much!

Ben

 

[mr2.0]

Got some pic of new paint job Ben? By chance you pillar beded it in the rear too? Might be the scope, double check it just to be sure. Tam

 

[bunsen27]

What was the ambient temperature difference from when you shot the good groups versus post Cerakote groups? Temps in the 50's and lower can affect your ammo. There is a reason Lapua make Polar Biathalon.

Oh yeah and we need pictures.

 

[bschneiderheinze]

Cherakote can make a huge difference as I found out after painting an AR. did you coat the bedding area of the stock

 

[djdilliodon]

Did you clean the barrel at all? Not to familiar with cerakote so can't take a stab at that. In different temps wood stocks can swell or shrink and if not bedded can cause changes in accuracy at any time. If your handy you can easily tackle pillar bedding the stock yourself as well as glassing the action area along with the first 3" of the barrel channel.

 

[BenY 2013]

Ok I will get some pics of the rifle up tomorrow if I can, I can already say I'm pretty sure you guys will like it. It's a sexy beast!

The stock is pillar bedded both front screw and rear screw. I need to double check and make sure the barrel is completely free floated, I didn't think that the adding of Cerakote might could have made it touch some of the bedding in barrel channel. (I bedded 3in of a Lilja barrel in the barrel channel, it now wears a factory tube, so several thousands there but I need to double check) The stock is a Manners so it shouldn't be swelling.

I did not clean the barrel any, the temps were maybe 20 degrees apart. It's been around 40 degrees both times I think.

I may throw my other scope on and double check the free floated barrel. Any other recommendations? Action and barrel screw torque?

Thanks
Ben

 

[jbell]

If you are not careful when you applied the Cerakote and put it on thick it could need to be "rebedded" I have seen it more than one time. If the action is now very snug going into the stock that may be the problem. Especially on the CZ and Manners as I think that the action sits deep into the stock. But that is just a SWAG...

 

[djdilliodon]

Do both pillars make contact with the action? What did you use for pillars? With a properly pillar bedded stock your gun shouldn't be picky with action screw torque at all. I'm starting too think your swfa scope is a lemon . I would try and swap scopes again to see if she shoots like she was.

 

[BenY 2013]

I don't think the scope is the issue, if I have checked everything else I'll give it a look. It tracked well today and has in the past. Although I'm not sure it is sitting perfectly level..

I did look and the barrel is making contact with bedding in the barrel channel that was for the Lilja I had. Tomorrow I am going to float the barrel and see if there is an improvement. I may have coated the Cerakote a bit thick as it was my 1st time. More is less right??? Lol I'll check, but it fit snugly into after the coating but no more than before when it shot great if I correctly remember..
Any more suggestions?

I think I am gonna make a checklist for all of the rifles I put together. Any ideas of what should go in it?

Thanks
Ben

 

[Downzero]

If I had a 3/4 MOA .22, I wouldn't complain.

 

[BenY 2013]

Well 3/4" at 50yds is not good enough for me. I want a tight little clover leaf which I know the gun can do, because it has.

Took it apart and noticed some things. I'm not sure the rear pillar makes good contact with the bottom metal. It also has a layer of bedding material between the action and the top of the pillar. BUT it was like this when it shot .2 and .3" groups.

When the front screw is tight and I loosen the rear it stays tight, when I reverse that with the rear tight and loosen the front the barrel moves up ever so slightly. Still it was like this when it shot well.

Tomorrow I am going to completely float the barrel and make the rear pillar contact the bottom metal then go from there.

Ben

 

[jbell]

When the front screw is tight and I loosen the rear it stays tight, when I reverse that with the rear tight and loosen the front the barrel moves up ever so slightly. Still it was like this when it shot well.

Ben

As you may very well know this is a bad thing. I will usually put a dial indicator on it and see how much it is moving. I don't like any movement but have found from messing around with a few rifles that generally any thing over 0.002" is getting into too much stress and will show up on paper.

 

[BenY 2013]

As you may very well know this is a bad thing. I will usually put a dial indicator on it and see how much it is moving. I don't like any movement but have found from messing around with a few rifles that generally any thing over 0.002" is getting into too much stress and will show up on paper.

That's what I was afraid of... So what is the remedy? To re-bed the stock?

Ben

 

[jbell]

Yes, that's about it.

 

[n64atlas]

Try a shim in the rear just to see if that helps. Cerecoat does add thickness to all the metal. It might have been enough to put more stress on the action. This in turn could change how the bolt locks up. Same with pressure points in the barrel channel. Might have been free floated before the coating was applied, now it might be touching somewhere. If all this checks out, then the scope might be in question. Does it have thicker cross hairs than the other scope? Does it have a dot? I prefer very fine cross hairs. I think dots take up too much target area. Does your scope focus at 50 yrds? Do you have to be directly behind the scope for best cross hair aliment? If you still have the other scope, install it and see what happens.

 

[BenY 2013]

I floated the barrel and made sure there was some engagement in the rear pillar. Shot some more and it was a little better, but still not anywhere close to where I want it. I noticed some odd things while shooting.

Both today and yesterday this happened. I would shoot 15-20 of what it shot best with before(Eley Target), then I would swap to a different ammo(yesterday it was Rem. .38gr subs and today it was SK Standard Plus). The first group from each of the new ammos would group VERY well like it should in the .2 and .3s. It would do one group both days right after switching ammo and then back to the inconsistent shooting.. Anyone ever seen this? Tell you anything?

While I was cerakoting the barreled action did take about a 4-5ft. fall onto concrete, but I looked it all over and didn't seem to be a thing wrong with it. Powder burn coming out of the crown seems to be all even.

Tomorrow I am going to shoot with the scope that I shot the good groups with and see if there is any change. I am really racking my brain here.... If the scope isn't the issue I may hog out the old bedding and do that again.

Ben

 

[mr2.0]

As you may very well know this is a bad thing. I will usually put a dial indicator on it and see how much it is moving. I don't like any movement but have found from messing around with a few rifles that generally any thing over 0.002" is getting into too much stress and will show up on paper.

I'm no expert but I'm with Jbell on this, a little too much of cerecoat which creates gap between pillar and action + torque down= stress

 

[BenY 2013]

I'm no expert but I'm with Jbell on this, a little too much of cerecoat which creates gap between pillar and action + torque down= stress

Makes sense to me. I am gonna shoot with the old scope, just to be certain and if not into the bedding process I go...

Ben

 

[mr2.0]

Don't forget to post some pics, I would like to see what the rifle looks like as I just got a 455 vpt for Christmas. Don't forget about mkII chassis either lol

 

[BenY 2013]

I'll definitely get some pics of this rifle soon! And hope to get some work done soon on the chassis. This whole bedding issue has me thinking an aluminum V block would be nice..

Ben

 

[n64atlas]

I floated the barrel and made sure there was some engagement in the rear pillar. Shot some more and it was a little better, but still not anywhere close to where I want it. I noticed some odd things while shooting.

Both today and yesterday this happened. I would shoot 15-20 of what it shot best with before(Eley Target), then I would swap to a different ammo(yesterday it was Rem. .38gr subs and today it was SK Standard Plus). The first group from each of the new ammos would group VERY well like it should in the .2 and .3s. It would do one group both days right after switching ammo and then back to the inconsistent shooting.. Anyone ever seen this? Tell you anything?

While I was cerakoting the barreled action did take about a 4-5ft. fall onto concrete, but I looked it all over and didn't seem to be a thing wrong with it. Powder burn coming out of the crown seems to be all even.

Tomorrow I am going to shoot with the scope that I shot the good groups with and see if there is any change. I am really racking my brain here.... If the scope isn't the issue I may hog out the old bedding and do that again.

Ben

The group you shot when switching ammo, was using the Eley lube. Next group, not so much. You need to clean the barrel before switching ammo types. Every company uses a different lube and even different lubes for different grades of ammo from the same company.
When you dropped it, did it land on the muzzle? You might have a small dent on the crown that you can't see. Look at it with a magnifying glass. When is the last time you cleaned the bore? How many rounds do you shoot to season the bore before shooting a group? How many rounds did you have through it before you Cerakoted it? How often did you clean it before Cerakoting?

 

[jbell]

The ammo change is a good point. I find it usually takes 10-20 rounds before a rifle will "settle" back into shooting consistently with an ammo change (rimfire). I also don't clean the bore between changes, I just shoot. This is how it usually goes: shoot one brand for a while, then change, first or second group will be a screamer then it will open up for a group or sometimes two, then start shooting consistently.

 

[russ10x]

If you clean your barrel, then expect to shoot any types of small groups, you are mistaken. I have a friend who cleaned his kid's 3P gun, it took about 300 rounds for it to get back to what it was before.
Everyone here, you are shooting lead by the most part. It self laps the barrel. My Uncle's 1930's Eric Johnson Winchester Mod 52 out shoots anything I own. It is a 6 groove barrel. To my knowlege, it has never been cleaned by him or me, with the exception of the bolt face, and chamber. Just my opinion....

 

[BenY 2013]

Yeah I don't clean the barrel between swapping ammo and don't think I am not going to start. I think the only reason you could get me to clean a barrel is if it was rusting or not shooting at all. Seen too many accounts of guns not shooting the same after being cleaned.

I think the muzzle is fine, I don't think that's where it landed. I wasn't in the room when it fell sadly....

I am gonna bed the rifle today. Any pointers.?

Ben

 

[djdilliodon]

Yeah I don't clean the barrel between swapping ammo and don't think I am not going to start. I think the only reason you could get me to clean a barrel is if it was rusting or not shooting at all. Seen too many accounts of guns not shooting the same after being cleaned.

I think the muzzle is fine, I don't think that's where it landed. I wasn't in the room when it fell sadly....

I am gonna bed the rifle today. Any pointers.?

Ben

Your stock is pillar bedded and those pillars make contact with the action (they should and I assume they do) so that will retain the placement (height) of the action within the stock. Using a gouge remove 1/16" min or 1/8" max of material in all areas to be bedded. Do not skim bed the stock. Do it the right way! Use devcon plastic steel puty for bedding material.

 

[TOP PREDATOR]

agree with the above on the cerakote, bedding, and temp difference, different scope, and ammo swaps causing some issues, with all of it happening at one time it's hard to armchair what it is. personally, i'd be most concerned with the 4-5' drop onto concrete.

did you cerakote it with the base & rings on? if so, perhaps they became loose after the impact, or cerakoted with them off, the base / rings aren't gripping like they should to the dovetail. did you retorque the barrel after the impact?

would that high of impact bend a barrel or where it connects in the receiver, even slightly enough to throw the accuracy off? were the action screws in it to protect the threads? maybe your screws are screwed if it hit on them.

i'd get rid of the excess cerakote first in the important areas, recheck clearances, use the 1st scope, recheck torque settings on everything, stick to 1 ammo, basically starting from scratch.

if it's still .5-.75ish, welcome to your cold weather dope. 20degree swings will do that, even at 50yds and good equipment.

back when it gets warmer out, if it doesn't go back to .2-.3, i'd think the barrel or where it goes into the receiver has a problem from the impact.

 

[BenY 2013]

Well I just got finished sitting it into some Marine-Tex, I roughed out ALOT of material. A little worried that I didn't use enough bedding material vs the amount of old bedding that I removed. I'll see if it was enough or not tomorrow. If it needs it then I'll do it again tomorrow.. Seems to always be my problem.

It was a bit more difficult to see the release agent with the Cerakote, but I feel like I got the action covered completely.

I do however feel like I got it to better bottom out on the rear pillar this time. Time will tell.

Ben

 

[jbell]

Good luck and let us know how it turns out.

 

[BenY 2013]

I certainly will! You know all of this bedding issue has got me thinking..... Just hear me out here..

What if, I was to make a "mini-chassis" much like the one Manners offers for the Rem. 700 and install it for the CZ. I guess it would just be like an aluminum bedding block. The "v" would allow the action to be centered every time without problem in theory. It would also act as a "super pillar" as well.
Thoughts?

Ben

 

[justin amateur]

I'd be willing to watch you try it, but is it worth the effort when epoxy bedding
produces an exact fit in a Manners carbon-fiber/fiberglass/epoxy stock?

 

[jbell]

If you have a full machine shop and the time go for it, but a vee block bedding as in any chassis made will never be better than a proper stress free pillar bedding job. A chassis system as you are talking about is a "one size fits most" system and is designed to be a drop in aftermarket option for people who may use one stock on several barreled actions or just don't want to have their rifle bedded. In theory a vee block should be all you need for a round action but not all actions are true on the OD, also you lose surface area when going from a conventional bedding to a vee block system. If you were to also true the OD of your action then you would have something, but it seems like a lot more work to me than just bedding it again. Just my .02

 

[armorpl8chikn]

A lot of good info already here. What Bunsen, atlas and Bell said, spot on.

 

[BenY 2013]

I do have a full machine shop at my disposal manual and CNC equipment. I certainly wouldn't try it out on my Manners stock. I may look around for a cheapo wood or that black synthetic they offer and give it a try. If I do I'll keep you guys updated, for now though I will stick with bedding. Although this may be a soon to come project!

Ben

 

[jbell]

Well then it sounds like a very simple project. There is a simple test you can do to see how your action will work in the vee block system. I would assume that having a machine shop you probably already have a large vee block laying around that is machined true, if not it should not take much effort to cut one out of some scrap stock you have kicking around. You could then strip your action down and use some layout ink / Prussian Blue and check the contact of your action in it. That will tell you everything you will need to know before you go to the extra effort of machining the vee to fit the action screws, magazine and trigger reliefs. Just a thought...

 

[BenY 2013]

Well then it sounds like a very simple project. There is a simple test you can do to see how your action will work in the vee block system. I would assume that having a machine shop you probably already have a large vee block laying around that is machined true, if not it should not take much effort to cut one out of some scrap stock you have kicking around. You could then strip your action down and use some layout ink / Prussian Blue and check the contact of your action in it. That will tell you everything you will need to know before you go to the extra effort of machining the vee to fit the action screws, magazine and trigger reliefs. Just a thought...

Precisely! I also remembered that I have a laminate stock that I built for another CZ 452 that I had, love the stock, just getting rid of the gun. So I think that I may fill in the inletting for the old one with some type of epoxy and then insert the "mini-chassis". But that will come at a later time! Right now I am still waiting to pop out the action. How long do you guys normally wait? 24 hours is what I usually do. I am so anxious...

Ben

 

[komishe]

BenY,
How did you plug the chamber for coating?

When I Cerakoted mine, I masked the entire chamber side of the barrel.
I didn't want to add any extra material between the bolt and barrel.
I am the farthest thing from a gunsmith, so I figured it was best to leave it alone, since I know nothing.....


I'm with the guys who do not clean between ammo selections. It usually shoots a little wily for 5-20 rounds and settles down.

Best of luck with the new bedding.
-Komishe

 

[BenY 2013]

BenY,
How did you plug the chamber for coating?

When I Cerakoted mine, I masked the entire chamber side of the barrel.
I didn't want to add any extra material between the bolt and barrel.
I am the farthest thing from a gunsmith, so I figured it was best to leave it alone, since I know nothing.....


I'm with the guys who do not clean between ammo selections. It usually shoots a little wily for 5-20 rounds and settles down.

Best of luck with the new bedding.
-Komishe

I used high temp plugs. Kind of a hard rubber that tappers down. I shoved them pretty deep into the chamber and muzzle so the Cerakote would not leak into either area. I did get a bit of Cerakote inside of the action, but it was just a very very small amount there around the chamber. I didn't paint the bolt I oxidized it. And it was like that when I shot the good groups. If this bedding doesn't fix the grouping issue then I will look into this more.

Ready to get this thing rolling like it should be! Tire of waiting on epoxy to dry to find out if it is right or not....

Ben

 

[BenY 2013]

Well it was as I feared. There wasn't quite enough epoxy for the amount of old material I removed. It was also too cold in the shop for it to cure properly(didn't read the fine print.....). So brought all of my bedding crap into the house. Gonna let the stock sit inside of the warm house for another 18-24 hours and tomorrow hog out most of the old marine-tex and this time be sure to use enough! Then let it sit inside of the house to cure after that.

This aluminum v block is sounding better and better to me. I think I am going to try and draw something up in Solidworks and get some material ordered soon. I appreciate all of the help from the Hide members, I am extremely ready to get this rifle shooting correctly!

Ben

 

[jbell]

I hear ya on the frustration of finding lost accuracy, but in a sick way I kinda like it... I usually wait 24 hours to cure as well. I also like to use a heat lamp to help keep the temps up, especially here in Maine in the winter. I work in my basement which is in the 50's during the winter, so after all the spillage is cleaned up I bring it into the living area where my kids mandate that I keep the heat at least on 60 (I am a bit of a scrooge with the heat, that stuff cuts into gun money fast!) and use the heat lamp. You can pick them up really cheep a your local hardware store. Just a thought... Also make sure you have the mix right, if it didn't cure well you may not have enough catalyst. The mix should be creamy and easy to spread but not runny, just a bit thinner than peanut butter (not the chunky stuff).

 

[BenY 2013]

The mix was like you said so I'm pretty sure I had it correct, I do like the heat lamp idea. I think I am going to stick it in the living room where we have the fireplace. Tomorrow I'll let it cure while inside of the house. I do have to admit that experience it the best teacher. I am certainly learning alot of small, yet very important things.

Ben

 

[jbell]

I do have to admit that experience it the best teacher. I am certainly learning alot of small, yet very important things.

Ben

That is the most important part...

 

[BenY 2013]

Ok so I just popped it out of the bedding again and it looks decent. Although there is an air pocket around the tang that is about the size of a quarter. Also it looks like there may be a bit of Marine-Tex between the action and the pillars. It was like this when(epoxy between action and pillars) when it shot so well. But along the sides and edges of the tang it is solid with no air pockets. Just that space right in front of the rear pillar. You guys think it'd be ok to go from here or do I need to re-bed again. I am really having trouble with this...

How can I keep it from getting epoxy between the action and the pillars if the pillars are already installed? Thanks

Ben

 

[justin amateur]

Stop second guessing yourself. It's a rimfire, not a .308.
Take the rifle as is to the range and shoot it, see how it works.
If I can get away with pillars and epoxy shims, you oughta be fine.

 

[djdilliodon]

Ok so I just popped it out of the bedding again and it looks decent. Although there is an air pocket around the tang that is about the size of a quarter. Also it looks like there may be a bit of Marine-Tex between the action and the pillars. It was like this when(epoxy between action and pillars) when it shot so well. But along the sides and edges of the tang it is solid with no air pockets. Just that space right in front of the rear pillar. You guys think it'd be ok to go from here or do I need to re-bed again. I am really having trouble with this...

How can I keep it from getting epoxy between the action and the pillars if the pillars are already installed? Thanks

Ben

Can you take a pic of the inlet area that you bedded and post a pic?

 

[jbell]

You can just shoot it to see how it shoots. The air pocket could just be cosmetic and not bother accuracy. Also as far as the bedding between the pillars and the action you should only have a thin point of contact down the center of the pillars and the rest be bedding, Round action and flat pillar. Here is what I mean:

 

[BenY 2013]

Thats the thing, I don't and didn't ever have that the small portions of aluminum you are showing in the pics front or back pillar. It wasn't like that when it shot well and isn't now.

I installed the rear pillar the same way jbell installed the pillar in his 455 build thread. I still seem to get epoxy between the pillar and action whenever I bed. And when I try to put less epoxy around the pillar trying to change this I get an air pocket to form. Really confused. Maybe in the future I need to install the pillars and bed at the same time so the pillar will already be bottomed out to the action.

So you guys think it might be ok if the pillars have epoxy between itself and the action? With torque applied with the epoxy hold up to it or compress such as wood or something? If you guys think it would be ok I will try and get it back together and shoot it soon. It really means alot that you guys are helping me with this. I greatly appreciate all of the info!

Ben

 

[justin amateur]

Compressive strength Marine-Tex gray = 13,000 psi

In the Manners T4 carbon fiber/fiberglass/epoxy stock
the pillars aren't all that critical, the stock is strong enough.

Go shoot it

 

[BenY 2013]

Thank you sir. I will get busy with the dremel(until I get back to a milling machine) and clean up all of the magwell and trigger area and get back with you guys. I am still pretty disappointed in my bedding job. I may end up redoing it eventually if the gun shoots well. If I were to buy a gun that had this air bubble or pay for it to be bedded and have this air bubble once done I wouldn't be a happy customer.

And since this is my dream to one day build custom rifles I am eventually going to fix this, either with glass bedding or my aluminum bedding block idea. But for now at the moment I am just going to make sure I can get the gun shooting again! I very much appreciate all of the help!

Ben

 

[djdilliodon]

A little trick for you in the future when glass bedding. Buy yourself one of those cheap black and decker orbital sanders. With no sand paper on it of course hold it against the stock when all the bedding is in place and let it vibrate for a min. This will remove the air pockets. Is marine tex a liquid or putty (thick like peanut butter) type epoxy?

 

[BenY 2013]

A little trick for you in the future when glass bedding. Buy yourself one of those cheap black and decker orbital sanders. With no sand paper on it of course hold it against the stock when all the bedding is in place and let it vibrate for a min. This will remove the air pockets. Is marine tex a liquid or putty (thick like peanut butter) type epoxy?

That's a really good idea, I'll have to remember that! Marine-Tex is just a little more runny than peanut butter, it is a putty and stays in place pretty well. That's why I am using it. I have also used JB-Weld in the past, while it was a bit harder to get to stay put the JB-Weld seemed to work fine as well. A good bit cheaper too! I'd still like to give Devcon a try one day, but at the moment I have plenty of Marine-Tex and it is working perfectly fine for me. Thanks again for the tip!

Ben