AI?

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10-96

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Not to hijack Bbarn's threat, his question did lead me to a question of my own.

I recently picked up a CZ 527 in 7.62x39. I've only made it to the range with it once so far, so I can't really say how I feel about it yet. But anyway, I got to wondering if anyone here has seen, done, or looked at the numbers from a 7.62x39 AI?

I know, it sounds silly to me too, but ya gotta admit, there's not much new under the sun, and if nothing else- it would make for some interesting Ken Waters style reading.
 
It sounds interesting to apply the Ackley treatment to the 7.62x39 for a bolt gun. So far I've not seen nor heard of anything like that. It would be expensive since the chamber reamer and dies would both be special order items...

Tony
 
In PO Ackley's book, he says that the cartridges that benefit the most from "improving" are cartridges with a lot of taper to the case and shallow shoulder angle. I think the 7.62X39 fits into that category pretty well. For a bolt gun, an increase in pressure is not an issue (within reason), so you could even hot-rod it a little bit. Give it a try and do a write-up of before/after velocity and accuracy.
 
You might look into the PPC series of cartridges and the .30 Walker.
They may not fall exactly into the 7.62 x 39 AI pattern,but its a derivative of x39 brass ,30 deg shoulder and straightened body.

Reamers,dies,etc will be much easier.
 
If you are looking for more power than the 7.62-39 you might just jump to a 300 savage or 308. You will never get enough extra powder in that case to come close to matching those rounds. Why not just enjoy the round for what it is?

If you need an AI chamber to make your round of choice an effective hunting round then you are way undergunned to start with.
 
Naw, I wouldn't have the means or ability to do a x39 AI. And, I suppose it would put in the .300 Savage ballpark, but it was just fanciful thinking. But on the other hand- it would juice up my CZ 527 a bit and be something to give my buds a few "Ooohs and Ahhhs". But I would like to see what it's capable of...
 
Chamber reamers are chamber reamers. Meaning that if you call Pacific Tool and Guage the price for a custom reamer isn't extreme.

Custom dies however...

Option is to get die blanks ($20) and have reamers made for them. Saves you about $400 or more.

If you want to do 7.62x39AI, i say go for it!
Let use know how it works out. I may be interestef in one too.
 
I say go for it!

Unremarkable results are still results. I mean, if you find that all you have done is made an expensive .308, then you can write it up. Research is often it's own reward. Also, models and extrapolation are good guides, but not a substitute for real world results.

As others have said, a custom reamer can be machined for. 7.62x39 as easily as any other reamer. Then, you can get a gun Smith to ream a die blank for you with the same reamer.

One big upside is that you would have a bunch of cheap brass to Ackley up. And you would have the only one I have ever heard of.
 
I'm sure if the OP wanted to carry a 308 rifle ,he could.
I think the point is the CZ rifle. It won't hold a 308.
The 6.5 Grendel is a worthwhile cartridge based on the x39.Case taper is straightened out and it has a little sharper shoulder.
Same with the very successful PPC cartridges.Based on the .220 Russian,which is essentially an Ackley'd x39 case,maybe with a slightly less sharp shoulder.
This has all been done.
There is a cartridge called the 30 Walker.Its a 30 cal PPC.
This link will get you an article about a 30 cal version of the 6.5 Grendel.
Is it worth it?Thats up to the OP.
I think I saw 2500 fps with a 150 gr Sierra boat tail in the article.Standard 7.62x39 is about 2400 with a 123 gr bullet.

This may not be exotic enough for full custom die and reamer prices. You might be able to conjure up a seating die with a chamber finish reamer,but not a sizing die. Obviously you can't resize cases by chambering them. It takes a separate reamer. Now,PTG or equiv can take a dull chamber reamer and regrind it to a sizing die reamer. You will still have a soft die .

A conversation with Redding or Forster customer service MIGHT produce something as simple as a 6.5 Grendel bushing die with a 30 cal bushing.
A Wilson type straight line seater might work out.

For myself,a CZ in 6.5 Grendel would be sweet,but that is a re-barrel.
Brownells handles a Howa small bbl'd action in 6.5 Grendel for more or less $500.

http://bulletin.accurateshooter.com...5-grendel-necked-to-30-caliber-beats-300-blk/
 
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I see a few reasons this is fools' play.
The AI "concept" involved the capability to use factory standard chamber ammo in the AI chamber. How's that going to work with steel case ammo?
The x39 design is purposely tapered to facilitate chambering and extraction in military weapons. Expanding the shoulder area to the extent that most AI designs use would likely split even brass case.
In the old days, rechambering to an AI design was a CHEAP alternative to buying a different rifle or barrel. Current gunsmithing costs virtually negate this cost savings. Why not just choose a cartridge that suits your needs?
 
I'm not particularly advocating for the project.
I'm advocating having some respect for folks with ideas different than what I might do.
I'd like to think we can discuss our ideas and priorities without some arrogant rude disrespectful person calling us a fool.
What seems ignorant is the assumption anyone would consider fireforming or reloading steel cases.
Split the brass case? Ackley himself said the best cases to AI have substantial taper.Regardless,Lapua and Norma,and maybe Hornady brass is available in the PPC and 6.5 Grendel configurations which are of minimal taper.
I bought 500 .257 R virgin cases to feed my 257 R AI.Never was my plan to buy factory .257 R to shoot in my rifle.I never have.
Mobuck ,you seem to think the 6.8 SPC is a reasonable option to fit a deer cartridge into an AR receiver. OK. Enjoy.I'm not going to rain on your parade.
Why is it so hard to get that someone might want to boost the performance of the slick,small bolt action CZ?
A 150 gr Sierra at 2500 fps ought to be fine for 250 yds or so.
I'm sure our OP can get a $ estimate together and make his own decisions about 30 grs more bullet,a better BC and 100fps.

I'm not going to build one. I would not build a 6.8 SPC,either. But I don't feel at all compelled to put down folks who enjoy their 6.8.
In the mean time,I can treat his ideas with respect.
As ARX Enterprises explains in the article,you just neckup Lapua 6.5 Grendel brass. ARX Enterprises sells dies. HMMM. I bet they could even chamber a CZ barrel.No need to buy the reamer.
 
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Sounds like lipstick on a pig to me. As mentioned, you won't see much 'improvement'.
"...The AI "concept" involved the capability to use factory..." Just for fire forming. Steel cased ammo is low end stuff anyway. If you're going to play with modifying a rifle and cartridge to AI, you're not likely to be using low end ammo.
.220 Russian(5.56 x 39) is just a necked down 7.62 x 39. Allegedly for deer hunting .
 
"Mobuck ,you seem to think the 6.8 SPC is a reasonable option to fit a deer cartridge into an AR receiver. OK. Enjoy.I'm not going to rain on your parade.
Why is it so hard to get that someone might want to boost the performance of the slick,small bolt action CZ?"
No problem, just choose a starting point with at least minimal chance for success(like having the action re-barrelled to 6.5 Grendel or one of the numerous wildcats based on the x39 case). The 6.8 is "plug and play" with a proven level of success.
"Split the brass case? Ackley himself said the best cases to AI have substantial taper"
Most likely Ackley was referring to the advantages of cases with more taper vs cases that already have minimal taper. The ability to fire factory ammo in an AI chamber was touted a a "big advantage" in case your AI ammo got lost, damaged, or forgotten on some long distance trip-not just as a way to fireform cases.
 
The 6.5 Grendel is a worthwhile cartridge based on the x39.Case taper is straightened out and it has a little sharper shoulder.
Same with the very successful PPC cartridges.Based on the .220 Russian,which is essentially an Ackley'd x39 case,maybe with a slightly less sharp shoulder.
This has all been done.
Click to expand...
Kinda what I've always thought--it's spawned some worthwhile children--ya never know...:D
 
That .30 ARX is an interesting looking caliber that would make a good round in a lightweight deer rifle. That is if the dies can be found. A quick search failed to turn any up.

Tony
 
The ARX website says the dies are available but I wasn't able to find them on their site... The dies they do have are expensive at $225 for a set. So you'd really have to be sure you want it before making the decision.

Tony
 
I'm not interested in the 30 ARX--but already have a grendel redding bushing die that I use to make 6mm predator--can you simply use a bushing for the 308 neck-up and an expander?
 
I'm not interested in the 30 ARX--but already have a grendel redding bushing die that I use to make 6mm predator--can you simply use a bushing for the 308 neck-up and an expander?
Click to expand...

That concept went through my head.I would guess talking to a Redding (or other) customer service rep would be the best plan.I don't have the bushing dies and I don't know how the shoulder transition works out.
Good thinking!
Lee might be able to assemble components to make a collet type die,too.
Its possible if they see potential dollar signs in a new product they'd give a little support.
If you know someone with an EDM machine,you can alter the hardest dies to work.
For a bolt rifle,I'd just blow the necks out like I would making 35 Whelens or 40 basic out of 303.
 
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