Idea for 7.62x39mm

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Nolo

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Just a little idea for the venerable 7.62x39mm caliber:
What if you took 7.62x39mm and loaded it with a 175-grain .303 caliber (.311 inch diameter, same as the Soviet round, I believe) bullet to whatever velocity it came out to with acceptable pressure and modern powders? Would your range increase? Would the terminal performance of your bullet increase any?
Just kind of a little musings, I've always wanted to see what would happen with the 'x39mm cartridge with a larger bullet.
By the way, yes I do know that this would be far too long for the standard AK or M16 OALs, but I still want to know.
EDIT: By modern powders, I mean whatever you guys load with, which may or may not give a performance increase over whatever 'x39 uses, which according to Wikipedia is SSNF 50. I know I'm a Knox powder junkie in my designs (GunTech'll berate me for that, I'm sure. :)), but I'm sticking to the realm of existence for this one.
 
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My experience is that the 7.62X39 performs accurately, but nowhere near as efficiently as I hoped. .30-30 was my benchmark for efficiency in my very arbitary comparisons, and I don't have the numbers written down and I was hardly pushing max loads, but the bullets weren't moving with great speed.

Accurate, though, with the bullets I was using... Spire Points, IIRC.
 
I think you'd run into stabilization problems due to the twist rate being wrong for your bullet weight and length.
 
BTW, the seating depth is critical for good functioning in this instance... and the longer bullet goes in on the power capacity a good bit.
 
Basically, the 175gr bullet would have more retained energy at any distance over the 123gr, if you started them both with the same muzzle energy. However, the 175gr would be moving a lot slower, and it would have a steep trajectory. So it is a bit of a compromise to load them that way. They may possibly be more accurate, though.
 
I wasn't suggesting this as a loading for an AK or anything, but as a completely new prototype design. If the twist rate is wrong, I'll use a different twist rate.
I was just wondering if it increased the range and/or effectiveness any. Obviously, the anti-material effectiveness would be increased, because the bullet is bigger, but what about anti-personnel?
I know it would, but, for instance, the Grendel far outdoes the 5.56 M193 at ranges even though the M193 goes way faster.
So the real question is:
-How fast would the 175-grainer go?
-And is the BC of the 175-grainer good enough to give us a performance increase (or at least match) over the M43 despite the velocity loss?
 
What if you took 7.62x39mm and loaded it with a 175-grain .303 caliber (.311 inch diameter, same as the Soviet round, I believe) bullet to whatever velocity it came out to with acceptable pressure and modern powders?
Click to expand...
I use a load similar to this all the time in a Saiga, an AR-15, and a Ruger 77MkII chambered in 7.62x39; Hornady 174gr RN over 20-somethingish grains of H322.

Chrono'ed velocity is around 1900-1950 out of a 16" barrel, and it works out of a standard AK/AR action. The bullet's in this weight range are stoutly contructed (designed for 303/7.62x54R velocities) and likely won't mushroom well in really thin game (small deer) but should be just the ticket for hog.

The RN bullet design makes the bullet shed velocity pretty fast, but it's accurate and has adequate energy out to about 200 yards. Inside of 200 yards, it's a thumper. I've experienced no stabilizaiton issues with the bullet, but that's likely because of the RN design. (Remember that stabilization is a factor of bullet LENGTH, not weight.)
 
make on

why dont you just make some and then tell us how it went? I would be interested in seeing the outcome. I bet you could load it with faster burning powders for a higher velocity, but you might also blow yourself up. hehe. :evil:
 
It would probably give a performance increase even with slowed velocities. Consider the M855 versus the Mk262
 
I use a load similar to this all the time in a Saiga, an AR-15, and a Ruger 77MkII chambered in 7.62x39; Hornady 174gr RN over 20-somethingish grains of H322.

Chrono'ed velocity is around 1900-1950 out of a 16" barrel, and it works out of a standard AK/AR action. The bullet is stoutly contructed (designed for 303/7.62x54R velocities) and likely won't mushroom well in really thin game (small deer) but should be just the ticket for hog.

The RN bullet design makes the bullet shed velocity pretty fast, but it's accurate and has adequate energy out to about 200 yards. Inside of 200 yards, it's a thumper. I've experienced no stabilizaiton issues with the bullet, but that's likely because of the RN design. (Remember that stabilization is a factor of bullet LENGTH, not weight.)
Click to expand...
The RN bullet kinda defeats the purpose, though, because its BC would be low. However, that does tell me what kind of threshold I can expect for velocity, and, surprisingly, I was right on the money at about 2000 f/s out of an 18".
why dont you just make some and then tell us how it went? I would be interested in seeing the outcome. I bet you could load it with faster burning powders for a higher velocity, but you might also blow yourself up.
hehe.
Click to expand...
Aside from the "blowing myself up" statement, I cannot do that because I'm only seventeen and have no reloading equipment, nor a selection of 18" .311 caliber test barrels to do adequate tests with.
 
Interestingly, this appears to be one of the rare caliber cases where you can significantly change the weight of the bullet, keep the same relative chamber pressure and still end up with the same muzzle energy. Most of the times, when I've experimented in the past, the muzzle energy fluctuates significantly when you fiddle around with the bullet weight/velocity a whole bunch (while keeping CP the same).
Several people have brought up .300 Whisper. This cartridge really wouldn't be all that comparable as it is significantly faster (.300 Whisper is subsonic, correct? That's the whole point, right?) because it does not care about suppressors, but it merely trying to crank out more range from the 7.62x39mm platform.
EDIT: Now that I look at the supersonic versions of .300 Whisper, I see it is not so different. However, given the much larger case capacity afforded me by the 'x39 case, doesn't that mean I should see a bigger performance benefit, all things being equal?
 
Just a little idea for the venerable 7.62x39mm caliber:
What if you took 7.62x39mm and loaded it with a 175-grain .303 caliber (.311 inch diameter, same as the Soviet round, I believe) bullet to whatever velocity it came out to with acceptable pressure and modern powders? Would your range increase? Would the terminal performance of your bullet increase any?
Just kind of a little musings, I've always wanted to see what would happen with the 'x39mm cartridge with a smaller bullet.
Click to expand...

When handloading and using heavier bullets, after a certain point, you begin to realize diminishing returns. Your idea would be akin to loading say a 250 gr. or so bullet in a 308.
Regarding terminal performance, there are tons of variables. A heavier bullet, when compared to an identically constructed lighter bullet, penetrates further due to momentum. This is just a matter of physics. Sorta like comparing a small, light, fast moving bulldozer hitting a brick wall and a large, heavy but slower 'dozer hitting the same wall...sorta...:rolleyes:
There's an old cartridge called the 303 Savage. It's ballistically very similar to the 30-30 Winchester except it was factory loaded with a 190 gr. bullet as oppossed to a 30-30's 150 or 170 gr. bullet. The idea was to get extra penetration with the longer, heavier bullet. Odviously the idea flopped because the 303 Savage is all but dead.
When I was in my late teens, I experimented with really heavy bullets inmy 45 ACP...heavy as in 300 grs, both cast and jacketed. They penetrated alright, but really no more than a good 230-250 TC or SWC because the velocity of the large bullet was so low.
Regarding increased range, also when I was younger, long before computers and ballistics programs, I performed some calculations in an attempt to determine which had more effect on trajectory: velocity or ballistic coefficient. It was velocity. And please...don't quote me bullet drops at 1000+ yds. I'm talking about "normal" hunting ranges. Of course any sane person can look at loading data for a particular cartridge and compare different bullet weights and their maximum velocities vs. their respective trajectories.:eek:
Anyhow...neat idea!
35W
 
I cannot do that because I'm only seventeen and have no reloading equipment, nor a selection of 18" .311 caliber test barrels to do adequate tests with.
Click to expand...

That's no excuse!!

When I was seventeen, my best friend and I reloaded and experimented with all manner of cartridges. Most of my part time job went into funding my truck payment, fuel, dates and reloading components.

Those were the days...
 
Well, I'm not sure you can crank up the velocity on the 'x39 any more than you already do.
But maybe I'm wrong.
I still wanna try it... :D
Kris, you wanna buy me a good set of reloading dies and presses, 3000-ish rounds of .303 British, 3000-ish rounds of 7.62x39mm, about five or so different test barrels (20", please) and do all my homework so that I can work on it?
No, of course you don't.
It's alright, though, I realize you were being facetious. And yes, they were the days...
 
As soon as I get my Yugo back, I'll be trying some 160gr cast in that caliber...
Click to expand...

Look for the Lee 155 gr mold. I load it with 14.2 grains of 2400, and it is accurate, and super cheap.

No, of course you don't.
Click to expand...

You're not really learning anything if you're not part of the experimenting process. While there is something to be said for trying new bullet/powder/length/juju combos, you seem to be a little caught up in the tacticoolness of it... I can guarantee you that a 7.62X39 will kill just as well as a 5.56, which does just as well as a .308, and just as well as a .50BMG, provided you fulfill the most important obligation, which is to put it in the right spot.

I started reloading when I was considerably younger than you... a part time job goes a long way towards components, and you aren't testing for accuracy, apparently, just the effects on the target. To that end, an SKS in 7.62X39 could probably show you everything you wanted to know as a test bed about the cartridge on the cheap.

For this particular load, I can't say I really see the point, though. Provided it were subsonic, maybe...
 
I want to be part of the experimenting process. But I can't, currently. My current situation prevents any more that what I already do, which is kinda just dreaming, and that's not going to change until I leave for Texas in August.
I don't even get to shoot very often, much less anything like reloading.
 
CBS 220, it's the same mould just a tumble lube as opposedto lubegrooves, that's where the extra 5 grains comes in. it works pretty good in the 303, time to expand.
I like moulds that work for more than one caliber!
 
as said....these heavy bullets are used for sub sonic "silent" loads.

I've seen published data for the x39 up to 190gr.

Beyond that puts you into experimental territory...or so me thinks.

But that can be a fun place to be.
 
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