Bedding advise for a CZ 600 ZKK

S

sikwhiskey

CGN Regular
Rating - 100%
15   0   0
Location
Lethbridge
The BRNO 600 30-06 has a pop up peep sight and a flip up middle sight. The middle site also has a barrel screw on the bottom. I have bedded the tang, action and barrel, free floated the front of the barrel screw to the forend.
I Haven't fired it since starting this project, I'm in the process of refinishing the stock with tru oil and then re-checker the old "stamped" checkering and finishing the grind to fit Limbsaver recoil pad.
I am wondering what to do with the barrel screw? Not use it/fill the hole? Bed the whole length of barrel/no free float? Or try it as is, bedded up to screw and free float the rest, adding in forend pressure if required?
Im not sure what effect the barrel screw is going to have once on and tight, hence the reason i bedded all they way to the screw? Factory pillars on tang and recoil lug, barrel screw looks like it may bottom out without stressing the wood, won't know for sure until I remove putty and drill out bedding compound. Should I make a pillar for it?
1972 production date. Metal in great shape, recoil pad was falling apart and stock needed refinished, I really didn't like the stamped checkering so I had my first go at checkering, didn't turn out too bad. Far better grip now and looks better. Its coming along. Here is some pics. Any advise would be great.

IMG_0494_zps1fa91cfd.jpg
[/URL][/IMG]
IMG_0498_zpscb13c7df.jpg
[/URL][/IMG]
[URL=http://s741.photobucket.com/user/sikwhiskey/media/IMG_0500_zps652aee03.jpg.html]
[IMG]http://i741.photobucket.com/albums/xx60/sikwhiskey/IMG_0500_zps652aee03.jpg[/URL][/IMG]
IMG_0493_zpsdbfef4d4.jpg
[/URL][/IMG]
 
DRA said:
See this thread on Gunsite SA: http://www.gunsite.co.za/forums/showthread.php?12961-Show-me-your-BRNO-CZ/page20

Post #193 asks the same question and post #194 advises to remove screw and dove tail nut from under barrel as they have no use.

Does anyone have any experience with this?
Click to expand...

No - I have not changed the bedding on any of the ZKK's I own .. and they all shoot pretty well. Although I admit I am never sure how tight the forearm screw should be -- I just set it up "snug" ... not tight. You could try your now bedded rifle (with appropriate clearance around the barrel dovetail - as you have) with and without the dovetail nut and screw and also using different tensions and possible adjusting the tension for different loads. BUT I would keep both items handy. The factory went to a lot of trouble (and cost) installing this "feature" and I don't believe it was their intention to make the rifle inaccurate.


(Stock looks great btw !!)
 
I was thinking the same thing, why would they include it if of no use? But then again, I would assume an entirely free floated barrel would have greater accuracy potential.
Who has the answer??
 
A barrel does not necessairly have to be free floating to be accurate. If the pressure of the stock against the barrel is consistent then you should get repeatable performance.
 
I have many BRNO/CZ rifles.
I have only bedded a few of them and then only at the receiver. As was said, most shoot very, very well as they were built. But old age tends to crack and shrink some of the wood so I have bedded the receiver in some of those.

I normally leave the bbl screw as is. Snug is the correct tightness in my experience. Too loose, it tends to fall out. They had no locktite in the early 40's when they designed these rifles, so I believe they snugged up the screw like all their screws. Not 65 inch pounds - but just nice and snug. It is my belief that when it is snug and when the screw slot is parallel with the stock you are good.

However, on the rare rifle that doesn't want to shoot well, I have tried to very lightly open up the channel past the front bbl screw... to some degree of success. I think relieving some of the old wood shrinkage in the bbl channel helps out.

BTW - if you wish to discard the bbl screw and nut, drop me a pm and I will make you a deal on it.
 
Barrel channel is already relieved and bedded, forward of the screw is free floated. best I could get with hand loads prior to bedding was 1.5". I'm going to try it with the scew snug, then float the whole barrel and see what happens.
 
what are you using for ammo? My 06 BRNO/CZ were always happier with 165+ gr, usually 180 gr.
I find that as a general rule of thumb, older euro rifles tend to prefer heavy for caliber bullets and they generally like flat base bullets better.
 
Well, I removed the screw and dovetail from mine and it changed things dramatically for the better.

In the case of the CZ 600 ZKK, the barrel is not very heavy which makes it such a nice rifle to carry, even with a full length barrel.

Bedding out as far as the OPs rifle is negates a lot of the reason for bedding in the first place.

Wooden stocks have a habit of warping. It is next to impossible to stop it absolutely. The more contact the barrel has with the channel, the more issues there will be keeping accuracy consistent from one day to the next.


The factory inletting on these rifles is very good. The biggest issue with them is that the walnut used in them can be on the soft side, especially on the lighter colored stocks. Then as often happens they dry out a bit more over time and the retaining screws need to be tightened. Often, for one reason or another the bedding pillars get lost. This is a tragedy for the stock. When the pillars are removed or lost, the wood gets compressed when the retaining screws are tightened. This causes the mag well to be jammed against the bottom of the receiver and puts all sorts of other stresses on the set up which are all detrimental to accuracy. There doesn't need to be a lot of gap between the receiver inlet/guide rails and the top of the mag well but there needs to be enough to keep any pressure off.

Replacing the pillars is relatively easy. I am lucky and can turn them out on my lathe but for those of you that don't have a lathe, just go to your local archery shop and buy some of the cut off ends from the aluminum/titanium arrow shafts. Cut them to slightly over the desired length and chuck them up in a drill press or hand drill and file them to the desired length while turning. This usually gives a very square shoulder on both ends as long as you have cut the pieces relatively square in the first place. I used to use a pipe cutter of the type used to cut off copper plumbing pipe. The 5/16 diameter shafts are the ones you need.

Once you have pillars of the desired length, prepare the stock and the receiver/first couple of cm of barrel for glass.

Before clamping down the receiver into the glass tightly I usually apply a paper shim between the tip of the fore end and the barrel. Then I screw down the front guard screw so that it is just tight and the rear guard screw until it is just snug. This means the receiver won't have any stresses on it when torqued down to its final setting.

Another thing, I usually let the bedding cure for a week before taking things apart and cleaning up any mess if necessary. Once every thing is together and torqued down properly, take a sheet of writing paper and pass it under the barrel. Mark any spot that has resistance and clean out the channel at that point. If there is an obstruction like the one on the ZKK barrel, you should be able to by pass it and slip the paper in between it and the bedding pad just in front of the receiver.

That's my method and so far it works if I do my part properly. I'm sure there are other methods that have proven equally as good.

Glass bedding isn't difficult, just get your wife to read the instructions for you and guide you through it. I know how much men hate to read instructions so I thought I would include that.

Yesterday a fellow came over with a rifle that he couldn't take out of his stock for complete cleaning now that the hunting season is over for him. He forgot to use release agent on the receiver that was included in his kit as was in the instruction which he only read from the side of the bottles to get the right mixture of ingredients.

The rifle was frozen solid in the stock and I advised the owner to just leave things as they were and clean what he could with a parts brush and a piece of twine between the barrel and the fore end to get any crud out of it and just clean the rest of it as normal. He insisted he wanted it removed. DUMB. I asked him if he had $500 for a new stock as well as fitting and finishing/checkering. He could not get it through his head that the stock which was glued to his receiver would likely be destroyed by removing it and the receiver would likely require refinishing as well. He was under the impression that there is a magic chemical that would dissolve the glass bedding but not wreck the stock or ruin the finish on the receiver. He told me he was taking it to someone who knows what they are doing.

Fine with me. Please show me the finished work. I like learning techniques as well as the next person and I am not under the impression I know everything there is to know about this sort of thing.
 
Last edited:
Will show the finished work bearhunter, as you say this stock is well inletted and soft and light, filling the pores is taking the most time. I bedded/ free float the front part of the barrel mostly as a sealer against the elements. It won't take much sanding/inletting the bedding to free float the rear part of the of the barrel when the time comes.
I've tried all kinds of loads with this rifle, 150-180 grn bullets, lapua brass, federal and cci primers as well a numerous powders, can't get it past the 1.5 moa, which is still very acceptable.
Where could I find a new wood stock for this gun if I wanted to upgrade to heavier/ fine piece of wood and keep it under 1k? who to get to do the work? I'm a sucker for fine wood........
 
Check out BOYD'S in the US. There are also a few Canadian stock makers but they require a bit more work to finish. Richardson's make a nice product.

By the sounds of what you are doing, all should be well when you are finished.

I use an old and tested load with my rifle.

I use 60.0 grains of H4831 over CCI 250 magnum primers under 180 grain bullets. My rifle will deliver MOA or less consistently with this load as will my BSA, Remington and Winchester chambered in this cartridge.

I had the same issues as you with "standard" primers. I no longer use them for any loads in any cartridge. The consistency of the magnum primer is just to good to pass up. Even the match primers made by CCI work well as they are quite a bit hotter than "standard" primers.

This load works well in my rifle. There are other powders that work well. W760 and IMR 4350 are always good contender in the 30-06.

One thing to check out when you are shooting with scopes that don't have adjustable parallax or high end scopes that seem to be parallax free, how much parallax do you have at the distance you are shooting????

Most of my mid range scopes, including Leupold, have a fixed parallax free distance, set up in the factory, between 125 yds and 150 yds. Unless you hold your head in exactly the same position every time you look through the scope and shoot when you aren't shooting at the optimal distance, you will get shot dispersion on target that will follow the parallax deviation.
 
Trinimon said:
A barrel does not necessairly have to be free floating to be accurate. If the pressure of the stock against the barrel is consistent then you should get repeatable performance.
Click to expand...

This is absolutely true, but the easiest way to get consistent pressure on the barrel is to not have any.

All my pre-64 Winchester model 70's (with barrel screw) and four ZKK's have the barrels hanging off the receiver and all shoot well and can be removed and replaced in the epoxy bedding with minimal or no change to point of impact. Obviously a change in impact from wood swelling or warping is a non concern.

None of them will shoot worse than 1.5 moa, and even if playing around with barrel bedding and screw tension cut group sizes in half, I would not trade away usable consistency for a bit of unusable precision.

Sicwhiskey your rifle looks good. Big improvement.
 
You must log in or register to reply here.
Back
Top Bottom