CZ 527 Carbine 7.62x39
- Thread starter Stover Rover
- Start date
Speer 125gn Sp ref. 2213, Alliant Reloder 10x 29.9gns 470mm 18.5" barrel 2539fps 1790ftlbs.
I have used Quickload for years and found it to be very reliable, even with a couple of percentage points either way I am confident in this round reaching the 1700ftlb threshold.
Very encouraging.
But a quick reality check suggests that is a rather compressed load. According to my Lee manual Reloder10 has a VMD of 0.07456 so 29.9 grains would be 2.3 cc, but the useful case capacity is supposedly 2.03 cc.
If so you are going to have to be VERY careful about seating depth.http://leeprecision.com/cgi-data/instruct/VMD.pdf
The same data suggests that Archer's 26.7 grain load of N120 is a slightly generous case full.
Yet another reality check: Hodgdon's own data for Reloader 10x doesn't show a load for 7.62x39, but does have a load for 30-30 with a 130 grain bullet, so its comparable. 30.5 grains gives 2273 fps i.e. a miserable 1491 fpe.
Alliant Powder - Reloader's Guide
Does Quickload have any other suggestions ?
Very encouraging.
But a quick reality check suggests that is a rather compressed load. According to my Lee manual Reloder10 has a VMD of 0.07456 so 29.9 grains would be 2.3 cc, but the useful case capacity is supposedly 2.03 cc.
http://leeprecision.com/cgi-data/instruct/VMD.pdf
The same data suggests that Archer's 26.7 grain load of N120 is a slightly generous case full.
Yet another reality check: Hodgdon's own data for Reloader 10x doesn't show a load for 7.62x39, but does have a load for 30-30 with a 130 grain bullet, so its comparable. 30.5 grains gives 2273 fps i.e. a miserable 1491 fpe.
Alliant Powder - Reloader's Guide
Does Quickload have any other suggestions ?
Sorry not my case- one that was loaded for me
Does your job involve you with munitions or does this info come from a deep interest in the subject?
I've had another look around the Alliant website, and found something more encouraging.
They publish a load for 7.62x39 using the Speer 123 grain.
27 grains of Reloder 7 giving 2429 fps i.e. 1611 fpe. Not quite there yet, but according to the Lee VMD data there is room for another grain of powder before compression starts ... If the Lee data is pessimistic, maybe you are in with a chance.
Whatever, its going to be marginal.
They publish a load for 7.62x39 using the Speer 123 grain.
27 grains of Reloder 7 giving 2429 fps i.e. 1611 fpe. Not quite there yet, but according to the Lee VMD data there is room for another grain of powder before compression starts ... If the Lee data is pessimistic, maybe you are in with a chance.
Whatever, its going to be marginal.
Not sure why I am bothering to reply, but to answer your gibe, yes I am interested in the subject, its not actually very complicated once you understand the fundamentals, and yes you are quite close with your first question.
Sorry to have upset you but facts and data are what I do. Avoiding awkward problems and lashing out when frustrated isn't behaviour that impresses me.
Since you get your reloads from an RFD. I suggest you get on his case.
But there is no reason why you can't take the 7.62x39 up to much higher pressures than you can with a 30-30. Remember, if you are using quality brass you are talking about the same case as the 6mmPPC, and most benchrest guys are running the case well in excess of 60 000PSI! There are also reamers out there for the 7.62x39 improved (i 'spose with a lot of care, you might actually get away with just using a PPC reamer), which essentially gives you a .311 PPC cartridge. I'd be expecting 125 grainers at easily in excess of 2600 fps with that cartridge.
With respect to your comment that Mr Potts can't get deer legal KE out of a BR cartridge, i can only say he must have been only using a 6mmBR. You can get more than 2800fps with a 125 grainer out of the .30BR with a standard length barrel! However, putting a BR cartridge thru the CZ527 would take a bit of work, due to the extra diameter - the PPC cases seem the more obvious solution.
I have never understood why CZ haven't made a .22 or 6mm PPC on that action - i guess there isn't so much demand in Europe as far fewer folks reload, but i reckon a 6mmPPC in the 527 would sell like hotcakes in North America, down this way, and on your side of the channel. Especially now that factory brass in PPC is avaliable. As a varmint rifle the 6mmPPC is very close ballistically to a .223, but given the potential to throw bullets around the 80 grain mark, becomes a much better small deer cartridge than the .223 can ever be.
With respect to your comment that Mr Potts can't get deer legal KE out of a BR cartridge, i can only say he must have been only using a 6mmBR. You can get more than 2800fps with a 125 grainer out of the .30BR with a standard length barrel! However, putting a BR cartridge thru the CZ527 would take a bit of work, due to the extra diameter - the PPC cases seem the more obvious solution.
I have never understood why CZ haven't made a .22 or 6mm PPC on that action - i guess there isn't so much demand in Europe as far fewer folks reload, but i reckon a 6mmPPC in the 527 would sell like hotcakes in North America, down this way, and on your side of the channel. Especially now that factory brass in PPC is avaliable. As a varmint rifle the 6mmPPC is very close ballistically to a .223, but given the potential to throw bullets around the 80 grain mark, becomes a much better small deer cartridge than the .223 can ever be.
And the other PPC-type case i am suprised we haven't seen CZ chamber is of course the 6.5 grendel. I don't know that the 6.8SPC mentioned earlier has been nearly as popular as some here seem to think, but the grendel looks likely to hang around and would again make a great small deer round.
Me lashing out? Nope
Me upset? Nope
Just interested in your background since you are forcefully questioning the handloads in use.(and it was genuine question not a gibe in #26 so don't be so precious)
Is there any evidence that I doubt your words? (other than your comment that the components are not available when they are)
No there isn't!
Will I/have I started to act on what you have written?
As a responsible shooter I have a duty to investigate your points.
Am I greatful for to you for drawing my attention to the issue?
Of course I am, just as I am to any poster who adds to my knowledge, but, what I do now and in what time frame I operate is for me to decide.
Me upset? Nope
Just interested in your background since you are forcefully questioning the handloads in use.(and it was genuine question not a gibe in #26 so don't be so precious)
Is there any evidence that I doubt your words? (other than your comment that the components are not available when they are)
No there isn't!
Will I/have I started to act on what you have written?
As a responsible shooter I have a duty to investigate your points.
Am I greatful for to you for drawing my attention to the issue?
Of course I am, just as I am to any poster who adds to my knowledge, but, what I do now and in what time frame I operate is for me to decide.
I'd be cautious about whether the miniatuarised mauser action would be strong enough. And you still have to be able to fit enough powder into the case.
AFAIK the highest pressure cartidge for which the CZ527 is chambered is .223 Remington, i.e. 55000 psi. (SAAMI).
For comparison 7.62x39 is 45000 psi. 30-30 is 42000 psi.
But the 7.62x39 case head is .443" diameter c.f. .376" for .223. so one might expect nearly 40% more bolt thrust for the same pressures.
Put it another way, shooting 7.62x39 at its rated 45000 psi could already be generating the same bolt thrust as a very hot-loaded .223 at 62466 psi.
Anyway, according to a quick glance at 6PPC Cartridge Guide none of the loads quoted come anywhere near to 1700-1750 fpe so 6mm PPC doesn't seem to solve the problem for UK hunters.
There can only be so much energy contained in 2 cc of nitro powder, and I suspect that it's not quite enough.
Now that would be nice. Whilst Alexander Arms were demanding a licence fee from anyone chambering their design, and there was no standard, it remained a wildcat, unlikely to be of any interest to mainstream manufacturers.
Now that they have given up the trademark (since February this year) maybe we will see some interest. Personally I think it has missed its window of opportunity.
Even Alexander Arms seem to have doubts about the potential for excessive bolt thrust with hot loads. E.g. see 6.5 Grendel Cartridge Guide
6.5 Grendel ammunition from Alexander Arms operates at a safe and sane 49,000 psi.
...
Latest Developments--CIP Specifications on the Way
The cartridge is going through the CIP process and the detailed max specifications will be released at that time. These maximum specifications are in excess of the loads used in factory ammo for the AR15 due to bolt thrust limitations of the locking lug system. I have known Bill Alexander for many years and one thing he is safe and with hundreds upon hundreds of Grendel's out shooting without any failure, I would I say the proof is in the hand of shooters.
6mmPPC similarly suffers from being a non-standardised wildcat.
When a big manufacturer decides to introduce a new calibre it seems they often take a decent wildcat, make a few tweaks, rename it, then arrange for the specification to be standardised. Maybe this will happen ?
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There are plenty of CZ527 out there already in 6.5mm grendel running at +60 000PSI loads. The factory loads are just detuned for the AR system but you can drive it significantly harder in the 527, which is a very strong mauser-type front locking system made with quality CrMo steel. If there were any concerns about the ability to take 60 000 PSI, i'd just suggest lapping the lugs to ensure they are equally bearing the bolt thrust.
trapdoortrapper
Well-Known Member
I handled one of those a few years ago and really liked the feel. Very handy and light. First thing I thought was that I wished it was chambered in 6.5 grendel.
Maybe.
Now going back to the original post, Stover Rover grasped the fundamentals of the standard chambering. It doesn't quite make the (fatuous) requirements for English Roe, nor any larger deer. Nevertheless it is a well balanced round , ideal for the purpose (small deer, fox and vermin).
Providing you are prepared to handload the rounds and source the slightly esoteric components.
Load a 100 grain bullet properly and it would be legal for Scottish Roe too. But not in England. How daft is that ?
It seems silly to discuss this further. Trying to turn a very sweet well balanced rifle into a supergun seems to be missing the point.
That would be me then.
Hornet 6
Well-Known Member
So let us know how it's working for you.
I now have a slot for the 7.62x39, and will order one as soon as the funds are in place, probably next month.
I already have all I need to load some practise rounds, and will pick up a more suitable powder (A1680) when I next visit the gun shop.
Neil.
We are possibly talking on crossed purposes, I have the Grendel not 7.62x39. That said the Grendel is great, makes the numbers to make it deer legal and with the mod on is more quiet than a my modded .223. Oh and during load development it seldom produced a Grp over 1.5 inches at 100y.
, how are things going? Must be a couple of years since we met?
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