Switch Barrel Ideas for CZ 527

D

dogtrainer

Guest
I have a CZ 527 iin 7.62 x 39 and a second CZ barrel in 223 for the same rifle. I would like to switch between barrels while out in the field with the minimum of tools. The CZ 527 action head spaces off the internal shoulder of the CZ barrels.

Is possible to setup both barrels for hand tightening with index marks and then hold the action and the barrel together with a set screw with a plastic plug? The plastic plug prevents damage to the barrel threads.

I know that once I get the original (locktite) barrel free I can use nickle anti-seize on the barrel threads to make it easyer to put on and take off the barrels in the future.

Or do you have any other suggestions. I want to do this with the least expense possible but I want to do something that will work.
 
First off, the bolt won't work for both cartridges, as the 7.62X39 has a head diameter of .440" or thereabouts. The .223 has a head diameter of .378". Second, a plastic set screw to hold the barrel in place when working with pressures in the 55,000 to 60,000 PSI range would be an accident waiting to happen. You would need two bolts and the .223 barrel will need to be headpaced by a competent gunsmith. You will then need an action wrench and a barrel vice to switch between barrels. Hand tightening is not an option IMO.
 
Switch Barrel Concept

I have been talking to several gunsmiths about this project. The lastest information I have received suggest that I just need to index mark each barrel and the action for the place where the correct headspace is achieved.

One gunsmith said that when he sets up a switch barrel he threads it in and out of the action several times to find the ideal place and the ideal action-barrel tension before index marking the barrel. That way it will take years of barrel switching before the torquing of the barrel on and off will eventually loosen the grip between the barrel and action; in this condition the barrel will tighten past the index mark and the iron sights will be slightly off the 360 degree position on the top of the rifle, however, the rifle will still be safe to fire.

Are there any other ideas out there?

Additionally, a barrel removel wrench can be made to fit over the base of the barrel and held in place with a lock screw (that is threaded into the barrel) so that with a foot long handle, the torquing on or off of the barrel is rather easy; no vice is needed.

Are there any other pitfalls ?
 
dogtrainer said:
Additionally, a barrel removel wrench can be made to fit over the base of the barrel and held in place with a lock screw (that is threaded into the barrel) so that with a foot long handle, the torquing on or off of the barrel is rather easy; no vice is needed.
Click to expand...
Not on any of my rifles!
 
I don't think you are going to get anyone here who has tried what you are proposing, because most or all of them have actually changed a barrel. So they know how fine the tolerances are.

The threads might be 16 or 20 turns per inch, so one turn equals 50 or 60 thousandths of an inch. They are working to achieve errors in headspacing of less than .001, so they need to be well within 6 degrees of correct. That is hard to do by itself.

but when you realize that the threads are in effect an inclined plane, you realize that any forward force (that is, ignition of powder!) on the barrel will have a tendency to turn the barrel in such a direction as to increase the headspacing. I can't exactly calculate what the force would be on the setscrew, but with 60,000 pounds per square inch pressure available, I believe the force on the contact point of the setscrew might be rather large. In other words, it is unlikely to hold. The result might be tragic.

I have a savage action where you tighten up a large nut to hold the barrel exactly where you want it, to properly set the headspace. I found this was a ticklish operation. I was able to mark on the barrel the range of acceptable positions between where the GO gauge just went in, and where the NO GO gage began to go in. Tightening the large barrel nut has a small, but noticeable change in the headspace, so some trial and error is needed here. It takes me several tries to get it just the way I wanted it, and even then I was not exactly the same on 2 different tries (off by maybe 1/2 to 3/4 of a thousandths I think). You then put a 12 inch wrench on that 1.250 or so huge barrel nut, and rap it with a plastic mallet so that it is ON THERE and is not going to loosen. To get it off the first time (from the way the FACTORY put it on) I had to heat it with a heat gun for many minutes, and then use a heavy hammer on the end of the 12 inch wrench....probably an impact torque well over 100 ft lbs. A setscrew isn't going to even be in the same ballpark.

That's why these folks are cautioning you not to try your experiment. A much better alternative would be to switch to the Savage barrel nut way of doing things, recognizing that you are going to need two different bolts. On switchbarrel.com, they describe that some people have done "OK" with pencil markings on the barrels to show approximately where to tighten. Wtih a savage type barrel, you can be "OK" with good hand tightening of the 12 inch barrel nut wrench according to many sources. MOst put a little oomph of a light hammer rap once or twice. The Benchrest guys may think this is way too little, because they are used to having a firm stop against which they can put many many foot-lbs. However, it was the general conclusion on switchbarrel.com that using go/no-go gauges yielded a more repeatable point of impact than trying with pencil markings. And certainly safer! Again, this is an operation that takes maybe 15-30 minutes indoors in a clean environment. I'm not sure I woud try it in a real field, but inside a cabin with a table, it could be done. There are folks who say they can do it in 5 minutes.

A little care here will greatly reduce the chances of a tragedy. the savage barrel nut concept makes it a bunch easier, but it still takes some effort.
 
If you read or post on the www.savageshooters.com forum, you'll see many people who have done pretty much what you are thinking about. There is a vendor there who now sells barrels that can use the barrel nut for Rem 700 actions. These resources may give you ways to do what you want, but I'm not sure that they exist for the CZ action. You might be better off switching to a Rem or (easier) a Savage.

Carrying a set of go/no-go gauges would not be difficult, though I would just carry them in little cases to protect them from damage. You would need a set for each caliber. They are about $25 each, so you'd have $100 worth of go/no go gages. I have a .223 and a 6PPC set each. You want to stick with one manufacturer for the go and no-go on each caliber.

It would be easier if you picked two calibers that could use the same bolt, so you didn't have the risk of using the wrong bolt. Anyone can make a mistake and some mistkes are of consequence. Fellow in my dept got mixed up with a rifle/shotgun combo once and nearly lost his livelihood from the damage it did to his hand.
 
The CZ 527 Carbine is a very good walk about hunting-shooting rifle

Docsleepy, thanks for replying. Originally, I wanted to go the Savage switch barrel route but found out that Savage did not make a micro action; recently, I heard that they now have one.

I have changed over to lighter and more compact hunting equipment and the CZ 527 Carbine is perfect for my style of shooting and hunting.

The only thing left to do is expand upon a good thing and implement a switch barrel system for the CZ 527.

I want to avoid purchasing separate rifles for each caliber because it is difficult to travel with many rifles and it is also difficult to store many rifles.

Any final suggestions?
 
dogtrainer said:
Docsleepy, thanks for replying. Originally, I wanted to go the Savage switch barrel route but found out that Savage did not make a micro action; recently, I heard that they now have one.

I have changed over to lighter and more compact hunting equipment and the CZ 527 Carbine is perfect for my style of shooting and hunting.

The only thing left to do is expand upon a good thing and implement a switch barrel system for the CZ 527.

I want to avoid purchasing separate rifles for each caliber because it is difficult to travel with many rifles and it is also difficult to store many rifles.

Any final suggestions?
Click to expand...

You are not listening. What you propose is not safe. You will need an extra bolt at a minimum, AND a gunsmith to headpace the extra barrel and bolt.
 
How about an 8 to 10 twist 6mmBeggs bbl and have different ammo to suit your different needs? Light bullets for varmints and heavy bullets for larger game. This only works if you reload. A 6.5 Grendel might also work. No way to know if it will fit or feed from the mag without trying it. I would think the Beggs should feed fine.

IMO the whole bolt action switch barrel idea is overblown. If you think the two bbls with shoot to the same POA then you are dreaming. It is possible to determine what scope adjustments need to be made but that first shot will still be a worry. If you want a real switch bbl get a Contender or Encore and have the extra bbls already set up with a scope. A REAL switch bbl doesn't require tools.
 
I found a gunsmith

For less than half the price of a complete rifle I can have a second barrel (and the first barrel) set up as a switch barrel system including the cost of the bolt assembly.

I have found a gunsmith that will index mark the action and barrels, make an action wrench, and make wood blocks for a vice to hold the barrel during the switch.

The only thing left to do is figure out how to adapt a thinner magazine to the bigger opening of the existing magazine well.

Thanks for your help. I am on my way .
 
I have lots of experience with CZ 527 rifles. I'm the originator of the modified trigger guard and shortened magazine that over 200 folks have had me do..

I've customized them nine way till Sunday.......

www.rvbprecision.com

So, what you are proposing is nearly impossible. Finding a second bolt will be difficult as CZ does not sell bolts. And you will need a second bolt. Period

The magazines will never interchange. The 7.62X39 is much larger than the 223 series magazine. The CZ-527 has a cartridge specific trigger guard, magazine and magazine cut out. Nothing interchanges amongst the different chamberings.

In fact, there is so much hand assembly with these rifles, that it is rare that the trigger guard from one rifle even fits another rifle of the same chambering.

There are lots of folks that have switch barrel CZ-527 with the same cartridge size. 223, 204 Ruger and 17 Rem can be easily made switch barrel. And they will all feed properly from the same magazine. There are folks that have a 7.62X39 with switch barrels for 22 and 6mm PPC, and with a bit of fine tuning, these will feed from a magazine.

There is no need for all this index mark stuff you are talking about. The second barrel is simply threaded and head spaced by a competent gun smith and one barrel is removed an another installed with a very simple barrel vise (Midway - Brownells) and an action wrench that simply slides into the bolt races. The barrel vise can be clamped to the tailgate of a PU truck for infield swaps.

You will need to re-sight the rifle every time you swap barrels unless extreme accuracy isn't important. Iron sights will stay aligned as both sites are attached to the barrels.

Switch barrels are a fun project, but you need to know what you are doing. And in most cases it is cheaper and much more convenient to simply purchase a second rifle in the caliber desired.
 
CZ's 527 Are Fun to Use

RoyB,

Thanks for speaking up and supporting that the CZ 527 rifles are fine rifles and fun to use. That is why we are searching out more ways to have fun using these rifles.

The bolt assembly is available (depending on part shipments from Eastern Europe) from CZ-USA but it is expensive.

Because I wanted to keep the project simple and cost down I decided to re-chamber the 223 barrel to 22 PPC. That way I do not need a different bolt body, extractor, magazine, and magazine well-trigger guard assembly.

Because the 7.62 x 39 cartridge has a tapered body I think the 22 PPC loaded rounds will feed nose low on the feed ramp.

If this project concept works out, I will eventually order a 6.5 Grendel barrel and look for a 17 Remington barrel for re-chamber to 17 PPC. Ideally, both of these barrels will also have matching contours to the carbine barrel and the same iron sights; CZ's Carbine configuration in the model 527 is so handy.
 
EXCELLENT choices! Those PPC cartridges will shoot fine out of that action without a lot of fuss. Be sure to report back on how it all works out.
 
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