Home Forums Hunting & Shooting Gunsmithing Mentor me please on 1st Re-barrel

Here is what i am looking for. I am looking to have CZ 527 in 7.62 x 39 re-barreled to 6.5 Grendel. I am looking hard at a 1in 9 chrome moly barrel at 22" & threaded for a suppressor. Green Mountain has this overstock barrel from a discontinued Midway run.

Ok I have never done anything like this b4 so as the title says Mentor me please. I like the CZ 527 platform a lot and feel the Grendel would be the optimum highly efficient deer cartridge for this action. Been holding out for CZ to offer this rifle for some time now and I am finally caving in. I really want one of these in the Grendel.

With the chrome moly barrel what finishes should I consider? The smith that i am considering does not offer bluing. Would sending the barrel out for a nitride finish be worth considering?

Consider cerakote on either the new barrel or the entire rig once the barrel is finished and test fired. Cerakote would prove tougher than a blued finish. A 6.5 Grendel would be really nice. Can the round feed through the magazine??

For a walkabout rifle the CZ 527 in 7.62 x 39 comes up in searches as the most favored action to re barrel to 6.5 Grendel. Reports also indicate good feeding from the mag with no adjustments necessary. Suppose if a guy wished to load any really long bullets, the single shot follower may come into consideration.

All my research thus far indicates bullet weights of 130 grains to be max for consideration for this caliber.

Cerakote is being considered, though my preference would be a nitride finish for both the barrel and the action.

Trouble with Nitriding seems to be finding a vendor willing to do a one-off project. Advantage to Nitriding would be complete protection offered to both the exterior of barrel including threads for suppressor as well as the bore. Disadvantage of nitriding would be the hard finish would prohibit any further modifications.

If you want to shoot sub sonic get a faster twist for heavier bullets!! Is the Grendel sub-sonic with 140's?? That is the heaviest you will be able to stabilize w/ a 9" twist.

Had not really considered this Grendel as a subsonic rifle. I have just been around enough guys that have and do shoot a lot and their hearing is nearly gone. With this gun I intend on strictly shooting supersonic. Suppressor should still offer a lot in the way of hearing protection when not wearing ear muffs in the field.

Ill most likely do most of my subsonic shooting with a Handi 300 blk.

OK. I just thought you were using a bolt gun so you could go sub sonic w/o the cycling issues of an AR.

Guess for me personally an AR firearms have offered no appeal as of yet. Efficient and accurate bolt action rifles is where it has been at for me. My eyes have just been opened to the merits and accessability of a suppressor I suppose.

I see factory rifles threaded for an suppressor is just becoming somewhat common place and appreciate that in a polite sort of way.

OK Lets Try for more specifics. CZ chooses to locate off thinner face with a smaller diameter barrel as opposed to a shoulder to the face of the action. CZ factory rifles have a pretty good reputation for out of the box accuracy. Gunsmith I am considering has not worked on a CZ as of yet. Seems he would prefer to use the shoulder approach.

Seems to me if done properly the shoulder locating approach will offer a bit more stability at a cost of a bit more weight. A good share of the reason I am choosing the CZ 527 action is I was wanting a light weight hunting rifle. should I be on board with the slightly heavier barrel to provide a shoulder for this semi custom rifle?

I was thinking about this same conversion until I shot my 527. I put the conversion off. I was wondering the same thing as your smith. I was
going to put a shoulder on the barrel and face off the front of the receiver. Then turn the barrel to a Win feather weight type contour to minimize weight gain. Has anyone done it this way? I may look for another 527 that I can convert if the funds ever show up while I'm thinking about it. Cutting the magazine down a couple of rounds will make it even more fun haul around.

Couple notes: if you want a barrel with a shoulder your smith will need an action mandrel to accurately cut (and true) a few thousanths off the action ring face.
He will also need a lathe capable of cutting metric (1.25M) threads. Some use 20 threads per inch and cut threads until there is a sloppy but usable 'fit'. I have 527 rifles rebarreled both ways, with and without shoulders. I prefer the factory method NOT using a shoulder. Both ways work well, but the action looks and is lighter by a small amount by having a slimmer 'face fit' smaller barrel at the chamber area. If you go with a larger contour then fitting a new barrel with a shoulder will be fine. The CZ action as it comes is not 'truly flat' on the action ring face hence the need for a mandrel and trueing cut. It also gives you a FLAT ring face to measure from during chambering as well as contact the shoulder on your new barrel.

Hello Al

Smith I am working with seems very capable despite his young age. Based on my conversation with him it sounds if he intends to turn his own mandril. as for threads He is capable of pretty much anything with a CNC lathe he does his chamber and thread work on.

Looks like I am going have this heavier F34 contour threaded for supressor done on one action and on another action Ill have a 2nd lighter weight done with a E-bay S.S. 24" Lothar Walther pre chambered barrel bought with a make an offer. Ill have a old class mate I just caught up with, do the LW head space as 1st smith chooses not to work with pre chambered barrels.

I would really like to save one of the factory 7.62x39 barrels though I am loosing faith that is going to pan out. Have tried removing a 17 hornet barrel and a 7.62 x 39 barrel with no joy thus far. Simply have not found a means yet to adequately hold the barrel from spinning. Grr

Just remember to not over tighten the action wrench. The forward action ring is thin and actually will squeeZe tight onto the barrel shank in it! I've removed a half dozen or so CZ 527 barrels. After removing them I experimented with the tightness of the action wrench and was amazed at how little it took to make the barrel / action ring to squeeze tight onto a loosened barrel shank!
Ain't much steel in the CZ 527 action ring!
BTW- using only hardwood barrel blocks w/ Brownell's resin to hold. Some CZ barrel shank threads look to have had thread the or some substance on them. Apply KROIL a few days ahead of time. Can't hurt.

Thanks for the words of caution.
I have been keeping the action wrench tightness very much in mind. Just tightening enough to eliminate any play. Seems to me the wood blocks are inadequate for the task at hand. Would I be correct in my thinking that a good fitting aluminum bushing or a lead bushing will offer more holding capability? (Withstand more torque b4 allowing barrel to slip)

Went to some lead shims w Rosin in the barrel vice and some impact on the wrench handle Via a 2 lb sledge hammer. and felt like the imposable was achieved. Threaded off the rest of the way free as could be once she broke loose. A little Joy after all.

On to the 17 hornet with same approach. No joy here yet

Experience here with this challenging removal, leaves me really in favor of allowing a shoulder contact on the trued action face for the replacement barrel. Clearly this will not be an option with the Lothar Walther barrel. We will live and learn I suppose.

Off to see the smith tomorrow about the head-spacing for the Lothar Walther 6.5 Grendel barrel.

You can use either method and just not torque back on near as tight, AND use thread anti seize compound. How tight the factory joint was is not because they use the inner shoulder method, but they must occasionally use loctite and a LONG wrench handle! NOT necessary!
Most of my switch barrels are hand tight but are al right hand thread so shooting would tend to tighten the joint anyway. 25-45 lbs torque is plenty! Of course clean the action threads of any glue crap and also the factory barrel shank threads if you re use the factory barrel.

If I had my way I guess I would like to ask the going forward that the assembly team at CZ would only have tools available to them that would allow 25 fl lbs for example. As you mentioned the rifeling twist is only going to promote further tightening. Perhaps no males should be allowed to tighten these barrels and the ladies weighing more than 85 lbs would be dissallowed from this task as well.

I have seen it been expressed that the carbine rifles seem to be worse due to an effort to line up the sights. That being said I managed to get a sample of one carbine apart so far with considerable effort and I have one sporter American barrel I still have not been able to get to break loose yet. I have put forth much more effort attempting to break loose the 17 hornet barrel. Hate to say it though I am close to throwing in the towel on the 17 Hornet barrel removal.

The lead shims did go a long way twards allowing me to get a better grip on the barrels when removing the barrel from the action or attempting to do so.

OK lets focus on the Grendel project. Removal of the 7.62 x 39 barrel was truly a PIA IMHO up to the point the original barrel was broke loose.

Then things seem be going better from there. once broke loose original barrel threaded off easy as you might hope for. New barrel threaded equally as easy. checked head space at hand tight with a PTG Go gauge and tape. two thicknesses turned out to make for a snug bolt closing.
Torqued the barrel at an estimated 25 ft lbs of force.Then re-checked head space with 1 thickness of tape and found head space to be quit snug.

Dropped the barreled action back into the original stock and she was truly a free floated near perfect fit.

Only issue I have here came as no surprise to me the action needs to be bedded. Suppose I could have a gun smith look her over though I am confident she is ready to go after a bedding job and a good cleaning & mounting a scope.

Ok off to bedding the stock and start a load work up. followed by a barrel break in.dare say she will be ready for some load work up by or b4 next week.