CZ 527, 7.62x39 success

Counter-intuitive that the CFE BLK powder charge is more seeing that it's listed as faster burning than H4198 on their relative burn rate chart -

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Mauser vs. falling block action strength compared. The actions lock differently to withstand the thrust developed by expanding propellant pressure against the cartridge case head. The mauser uses a bolt with small dual lugs, and the falling block uses a massive block abutment. Stress-analyzed the same as a thick-walled pressure vessel under dynamic internal pressure loading but with different end closure designs. Insight presupposes a background in engineering mechanics and strength of materials. :cool:
 
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The 123gr at 2300fps zeroed at 100 yards hits with 1075ft/lbs.........at 200 yards -8.2" low and 786 ft/lbs.........at 300 yards -28.5" low and 569 ft/lbs
The 150gr at 2200fps zeroed at 100 yards hits with 1309 ft/lbs .......at 200 yards -7.4" low and 1053 ft/lbs...............at 300 yards -25.8" low and 842 ft/lbs
 
Slamfire said:
Counter-intuitive that the CFE BLK powder charge is more seeing that it's listed as faster burning than H4198 on their relative burn rate chart -

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Mauser vs. falling block action strength compared. The actions lock differently to withstand bolt thrust. The mauser uses a bolt with small dual lugs, and the falling block uses a massive block abutment. Stress-analyzed the same as a thick-walled pressure vessel under dynamic internal pressure loading but with different end closure designs. Insight presupposes a background in engineering mechanics and strength of materials. :cool:
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Are you under the impression that I am debating the strength of action between the M77 and No.1? If so, that would be incorrect... what I am saying is that whatever "super load" you are chambering in your No.1 can easily and safely be handled by the M77... the cartridge itself is the limiting factor for all feasible loads. Feel free to send that recipe by PM.
 
Interesting point, x39 case capacity might not be big enough for peak pressure duration to be long enough to get appreciable muzzle speed increases over standard in spite of higher operating pressure?

In a No.1 no magazine to limit COAL and generous throat length so that bullets can be seated way out for increased case capacity over standard. A few more grains at about 75 fps increase per grain adds up. Higher pressure at longer duration with the right powder helps. :cool:

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Back again... I thought I would add that I did a bit of a search for other rifles that produce a firearm with the 7.62 x 39. Its a Howa MINIACTION rifle. So I've added a link so readers of this thread can see something else that is out there - perhaps not in Canada at this time. https://www.legacysports.com/catalog/howa/howa-mini-action-rifle/

It looks like a decent size rifle and can be had with several options like a 20” lightweight, 22” standard & 20" heavy barrel options.

All that's needed is for Howa to manufacture some Left hand bolt actions and it wouldn't be too challenging to pick one up in the 7.62 x 39.
 
My Howa Minibolt shoots Federal Fusion 123gr sub moa groups with the factory ammo. I have started reloading so will see what I can cook up and see if I can milk some more accuracy. It is the 22" Standard barreled version not heavy barrel.
 
All bolt actions should shoot sub MOA or I'd sell it if bedding didn't cure it.You won't be getting the barrel heated up orange hot anyways so a heavy barrel is just more weight to lug around IMO.What I like about the 7.62x39 is it is miserly on powder like loading for a .223 except legal for medium sized game in my part of the country.Probably would make a good trapline/ beaver gun with hardball either.Not a bad idea to hoard a few cases of ball as with the way things are shaping up in the world embargoes and ammo supplies drying up are entirely possible in the not too distant future.
 
Slamfire said:
A few more grains at about 75 fps increase per grain adds up...
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When you are getting to the top of the case and into the neck, you will never get 75 fps/grain... you would be lucky to get 30 fps.... due to the way pressure builds in an empty space velocity/grain is NOT linear.
 
Slamfire said:
Need to be using propellant X. Speed increase supported by chronograph readings. Coolest little round to handload in a No.1 rifle. ;)
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I've loaded this cartridge with many powders and bullets... my experiences don't line up with yours... perhaps it's all in the mystery load.
 
Going to see how fast I can safely fire a 180gr RN .308 bullet from my No.1. I think 2150+ fps MV should be safely doable. Might need to go to propellant Y to do that.

Round nose bullets to be used because these should expand reliably at lower impact speeds compared to a spitzer. Could be a viable Moose rifle? Calling them in is a close range proposition anyhow. Of course I would need to have my gunbearer standing by to hand me my .416 just in case the situation changes. ;)

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Slamfire said:
Going to see how fast I can safely fire a 180gr RN .308 bullet from my No.1. I think 2150+ fps MV should be safely doable.
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I tend to stick with a bullet that is reasonably balanced to the case capacity, 110-150 for the 7.62X39... maybe 160's for giggles, more than that and the cartridge can't drive it quick enough beyond 50 yards for good terminal performance.
 
I thought that using a 150 grain bullet was pushing the envelope - for achieving best velocity - for the amount of powder - with the case limitation in mind. I'd be happy with that myself.
 
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