CZ 527 Bedding Questions

[RobertH]

I hope all of you are are well.

I have a walnut stocked CZ 527 that I believe suffers from climatic changes, and would perhaps respond to a bedding job. Basically I develop a group which shoots wonderfully, which when the rifle is next used two months later looks like a pattern plate.  A bit of random, uneducated tweaking with the stock screws, and it seems to be back on song.  I have read that the 527 action can be tricky and fiddly to install (With which I agree), and also I have heard conflicting reports regarding whether the magazine well of the CZ 527 should contact the action/receiver or not. I would greatly appreciate some thoughts on how to proceed.

 

Thanks in advance,

 

Robert

[Furyan]

If you look up cavedweller1959 ,Youtube

  Cz527 Glass edding 17 Hornet , and Cz 527 17 Hornet Glass bedding the pillars. Hope this helps i have done my 2 17Hornets thsi way and a .22 Hornet they all shoot very good now compared to straight out of the box.

 

 

[RobertH]

Thanks for that Furyan. I've seen some of his vids, informative and entertaining. I'll certainly have a look at those. I'm concerned about messing up a pretty stock, did you find it relatively painless?

[Furyan]

Yes quite easy , after sweating over night worried if i had screwed it up .

[Iantohorse]

Hi Robert,

When I re-asembled my cz527 after a drenching, I tried to put the magazine into the rifle after the barrel/action were in place in the stock.  It didn't seat nicely, and wouldn't shoot well.  When I put the magazine into the action, and then put it all into the stock, everything went well. So, my experience says, " put the magazine fully into the slot available for it "

 

[RobertH]

Thank you both for your helpful replies, it seems I have an embarrassing but interesting outcome. I stripped the rifle down last night and measured the stock and metalwork separately. I was primarily interested in what I have read on several sites about the bottom metalwork touching the receiver, thinking maybe they are contacting in such a way as to cause rocking or insufficient clamping force instead of clamping solidly to provide an adequate platform for the barrel. (this didn't appear to be an issue as my measurements suggested there was some .023" clearance between the top and bottom metal bits) Despite pulling the rifle apart three times and careful reassembling, at one point removing the nasty split-pin pillar on the rear action screw, and every time using your technique Lantohorse, of putting it together with the magazine in place (Good tip!) it still shot badly.

 

So, here's the embarrassing and interesting bit about which I'd appreciate some suggestions!  The Rifle is in 223 and  I developed two 60 gr V-max loads last autumn using the OCW system that, the last time I had need of the rifle, shot into less than .3 minute. If anyone's interested, one used Viht's book max of 24.7 gr of N133, but I settled for the other slower, more comfortable but just as accurate 23.8 grains of N133 (both at a coal of 2.215") which is quite short and a compressed load.  No pressure signs and an average MV of 3086.  Anyway, (please stay awake!) I made up 100 of these rounds with five times fired and neck sized Norma brass, together with 100 brand new Lapua cases.   BUT,  I had previously made the 100 Lapua cases up into the 24.7gr book max loads that chronographed at an average 3200 fps. A blistering, very accurate round that was nevertheless a bit of a flincher.  So I pulled the remaining bullets, about 85 and reloaded them to exactly the same specs as the norma load.   These are the rounds I have been using yesterday and today, until I thought to take out and try the Norma rounds which shot impeccably back into .3 minute. Why would a brand new case using a pulled bullet shoot a group of between 1.75 and 2 minutes compared to a neck sized one producing .3? I still can't quite get my head around it.      Anyway I am still considering bedding as a method of eliminating more variables. If you've managed to stay awake, I thank you.       Answers on a postcard etc.................

 

 

 

 

 

[Scrumbag]

Hi Robert. Am no means an expert reloader, but in the limited experience I have, I have never found that reassembled rounds shoot anything like as well as a round which has gone through the "entire process" of reloading.

No idea why, just don't. Hope that's some comfort if not help.

Scrummy

[Popsbengo]

My thoughts:   .223 cases are small and comparatively flimsy so pulling and reloading without sizing most probably has made a set of variable brass.  A loaded bullet will have expanded the neck a touch, so pulling and reloading without reforming the neck tension could be an issue.  Also the act of pulling could have distorted the case a tiny amount, again, not reformed by sizing in a die.

I'd write the batch off to experience and would expect the brass to return to a good condition after the next sizing op.

[RobertH]

Thanks both, it is a comfort!  I’ll shoot them as plinkers and start again. It’s strange my memory tells me I re-neck sized them, but as that would involve popping out a live primer, I probably just rethrew the new charge, reseated and crimped them. At least from now on my reloading notes are going to be more comprehensive!👍

[phoenix]

What method did you use to pull the bullets.

I've used both a kinetic hammer and a collet puller, and in each case the bullets showed some damage.

You lack of accuracy with those bullets may simply be a consequence of them having been pulled.

 

Cheers

 

Bruce

[RobertH]

Very true Bruce.  I use the Hornady collet tool set as lightly as possible, but yes there are always some witness marks. I'm pleased at least to have learned from it. 

[VarmLR]

You have to be very consistent with 223 brass if you're aim is consistently precise grouping and low ES.  It's a small case and I check my new batches by volume from a random sample of 10 and take an average.  I then batch them, if needed, so the cases are all within 1gr H20, no more, no less.

Your load for the 60Vmax of well over 24gr is a very hot load indeed and may prematurely bow the case heads so worth checking for loose primers with each reload.  I was using 31.6gr N133 under a 60g V Max and only got 4 or 5 reloads from PPU before primers started dropping out.  With a 26inch barrel that translates to 3150 fps and is accurate.  I now use Norma brass which is more consistent and lasts longer.

[Andrew]

My latest 527 American Varmint came with a new bedding system. There is a corresponding cut in the receiver to mate to the steel block. Bedding done at the factory. Shot beautifully right from the box.~Andrew

[VarmLR]

That's a big improvement on previous models Andrew for sure.  I had to get mine fully DEVCON bedded with pillar bedding at the rear (as standard) and it was more consistent when done.

[Andrew]

I had to pillar bed my standard American Grendel so I did three other CZ's at the same time. This new system was a real (pleasant) shock to me. I had grown accustom  to fighting CZ bedding. I wasn't looking forward to going through that again. CZ finally got smart.~Andrew

[Scrumbag]

That does indeed look nice, Andrew!

Any chance of some pictures of your other CZ527s and their bedding jobs?

Scrummy

[ejg223]

Once had a 527 in 223. Long while back....

Bedding pic before tidy up. Bedding and stock reinforcement all in one go. Carbon reinforcement runs under the bedding. Rifle shot extremely well and consistently well. New owner has not needed to re-zero in about 11 years 

edi

[Andrew]

18 hours ago, Scrumbag said:

That does indeed look nice, Andrew!

Any chance of some pictures of your other CZ527s and their bedding jobs?

Scrummy

The next time I have reason to remove the wood from one of my CZ's I'll take some pictures.
~Andrew

[Scrumbag]

5 hours ago, Andrew said:

The next time I have reason to remove the wood from one of my CZ's I'll take some pictures.
~Andrew

Thanks very much!

[Scrumbag]

Edi, that looks a good job!

[KABOOM]

On 4/23/2020 at 5:13 PM, RobertH said:

Thank you both for your helpful replies, it seems I have an embarrassing but interesting outcome. I stripped the rifle down last night and measured the stock and metalwork separately. I was primarily interested in what I have read on several sites about the bottom metalwork touching the receiver, thinking maybe they are contacting in such a way as to cause rocking or insufficient clamping force instead of clamping solidly to provide an adequate platform for the barrel. (this didn't appear to be an issue as my measurements suggested there was some .023" clearance between the top and bottom metal bits) Despite pulling the rifle apart three times and careful reassembling, at one point removing the nasty split-pin pillar on the rear action screw, and every time using your technique Lantohorse, of putting it together with the magazine in place (Good tip!) it still shot badly.

 

So, here's the embarrassing and interesting bit about which I'd appreciate some suggestions!  The Rifle is in 223 and  I developed two 60 gr V-max loads last autumn using the OCW system that, the last time I had need of the rifle, shot into less than .3 minute. If anyone's interested, one used Viht's book max of 24.7 gr of N133, but I settled for the other slower, more comfortable but just as accurate 23.8 grains of N133 (both at a coal of 2.215") which is quite short and a compressed load.  No pressure signs and an average MV of 3086.  Anyway, (please stay awake!) I made up 100 of these rounds with five times fired and neck sized Norma brass, together with 100 brand new Lapua cases.   BUT,  I had previously made the 100 Lapua cases up into the 24.7gr book max loads that chronographed at an average 3200 fps. A blistering, very accurate round that was nevertheless a bit of a flincher.  So I pulled the remaining bullets, about 85 and reloaded them to exactly the same specs as the norma load.   These are the rounds I have been using yesterday and today, until I thought to take out and try the Norma rounds which shot impeccably back into .3 minute. Why would a brand new case using a pulled bullet shoot a group of between 1.75 and 2 minutes compared to a neck sized one producing .3? I still can't quite get my head around it.      Anyway I am still considering bedding as a method of eliminating more variables. If you've managed to stay awake, I thank you.       Answers on a postcard etc.................

 

 

 

 

 

My thought would be neck tension was the culprit, after a resize things should return to normal. As for the bedding and climate issues sealing with spar varnish if contact surfaces are even, if not light sanding and seal. My CZ550 had lumps in the barrel channel once those were handled superb results, that stock is laminate not walnut. The split pin pillar prob caused troubles too. Best wishes for good shooting.