Terminal Performance of the 7.62x39

[XD45 7,124]

I have seen MANY discussions of 7.62x39 vs 5.56 and generally figured it boiled down to preference.

 

Recently I have been thinking more about the performance of different loads in each caliber. Not really one vs the other, but load vs load in the same caliber.

 

With my purchase of the M92PV which will eventually become my first SBR I have been reading everything I can find about the 7.62x39 out of short barrels.

 

In the end I can't say there is much real data out there on the subject. At least not published data.

 

One thing that I have found that startled me was just how INEFFECTIVE some 7.62x39 loads are. It can be summed up by these particular quotes from Dr Gary Roberts:

 

"WDMET (Wound Data and Munitions Effectiveness Team) collected extensive forensic data on over 700 7.62 x 39 mm gunshot wounds during the Viet Nam war. The predominant feature of this cartridge is the MINIMAL amount of damage it produces in soft tissue wounds, on par with FMJ handgun wounds such as those produced by 9 mm M882 ball."

 

"For example, in the 17 January 1988 Stockton school shooting, 30 of 35 kids who were shot lived. Of the five that died, all were shot in critical structure––head, heart, spine, aorta and none had damage to any organ not directly hit by a bullet."

 

This shows pitiful performance for a rifle cartridge. In both of the above cases, it was a blessing that it performed badly, but if you were to actually rely on an AK for defensive purposes it could get you killed. I find this unacceptable.

 

Some imported loads perform much better than others, but unless you have tested the particular lot of ammo you can't be sure because the foreign manufacturers are notorious for changing components. So Wolf Military Classic (which tests have shown to be a good performer) may not perform well if they change anything about the bullets.

 

This isn't a knock against the cartridge itself, or the rifles that use it. I am a kalashnikov fan from way back. Just a case of understanding the reality that all 7.62x39 ammo is not equal. This applies to 5.56mm as well.

 

The most consistent terminal performance is going to be from premium bullets which are designed to expand/fragment.

 

Just thought I'd share this. I assume many of you had already reached this obvious conclusion, but I know that there are lots of AK owners who don't know just how poorly this cartridge can perform with the wrong ammo.

 

[theorangeplanet 968]

http://www.youtube.com/watch?v=E8hL3WtKGY8&list=UU1UICFxcABkGg8Nj3X0dW8Q&index=5

 

Normal FMJ loads in 7.62x39 mostly just poke holes at close range and don't tumble soon enough to cause damage at most angles and in most people. At further ranges with the lost velocity, I'd suspect it to destabilize and tumble a little sooner in the body.

 

That being said, I highly suspect some serious bias regarding the report claiming wounding effects similar to 9mm ball. A bullet of similar weight to 9mm going TWICE as fast is going to cause more damage, period. That's simple physics.

 

I've been tapping as many of the YouTube ammunition experimenters as I can to do tests of Golden Tiger. GT has a huge air pocket in the nose... and I suspect it would tumble several inches sooner in gelatin than comparable FMJ bullets like Wolf and Tula.

[XD45 7,124]

That being said, I highly suspect some serious bias regarding the report claiming wounding effects similar to 9mm ball. A bullet of similar weight to 9mm going TWICE as fast is going to cause more damage, period. That's simple physics.

I have no desire to turn this into an argument (even though this IS the internet, and therefore all subjects must eventually turn into arguments), but there is no such thing as "simple physics".

 

Things don't always behave as you'd expect them to. I would NOT expect a rifle bullet to do the same damage as a pistol bullet but I have found my expectations to have little effect on reality. Evidence is not always what it seems to be, but when evidence clashes with expectation, it is usually expectation that is wrong.

 

Real doctors treating real bullet wounds are about as definitive as research on the subject can get. Dr Roberts is a well known, and highly regarded researcher in terminal ballistics. His research does not match my expectations. Therefore my expectations were wrong. I mean, how arrogant would I have to be to simply refuse to believe real evidence because it didn't match my personal beliefs?

 

It is not lightly that I surrender my preconceptions. I knew that a rifle bullet must do substantial damage to the human body. It only made sense. But apparently not always.

 

When something I believed to be true turns out not to be, I examine my preconceptions and the evidence. I try not to be wrong about the same thing twice.

 

After further examination, I have a better understanding.

 

There is nothing in physics that requires something moving faster to do more damage as it passes through the body. The energy a projectile carries only matters as much as that energy is transferred to the target. A pointed bullet which passes through without hitting major organs or bones, and remaining stable will transfer little of it's energy to the body. If it's moving fast enough it may transfer energy in the form of hydrostatic shock even if it doesn't upset. But how fast is fast enough seems to depend on a number of variables and evidently the x39 bullet doesn't have the right combination of speed and shape to create much hydrostatic shock.

Edited February 25, 2013 by Darth Saigus

[thebuns1 4,323]

While I do agree that some loads will perform better than others, I dont see this caliber being as ineffective as many may claim. I feel a well placed shot with one of the lower performing loads will offer better results than a poorly placed shot with a better performing bullet. I also feel that modern bullets will perform better than those from 40+ yrs ago. I dont want to see this thread turn into a pissing match, but bullet construction is vital to performance, regardless of caliber. And for the lack of terminal performance, I feel its a moot argument as any caliber will have its good and bad loads.

[XD45 7,124]

While I do agree that some loads will perform better than others, I dont see this caliber being as ineffective as many may claim. I feel a well placed shot with one of the lower performing loads will offer better results than a poorly placed shot with a better performing bullet. I also feel that modern bullets will perform better than those from 40+ yrs ago. I dont want to see this thread turn into a pissing match, but bullet construction is vital to performance, regardless of caliber. And for the lack of terminal performance, I feel its a moot argument as any caliber will have its good and bad loads.

The lack of terminal performance is not a moot point if you are shooting a bad guy who's shooting at you.

 

Yes shot placement is important. It goes without saying that shot placement is important. Can we just agree to that and keep the thread focused on the original point?

 

And it is NOT a caliber vs caliber discussion. PLEASE, NO!

 

It is just me pointing out what I discovered about the x39 that others may find useful.

 

AGAIN, NOT AN ATTACK ON THE X39!!! NOT AN ATTACK ON ANYBODY OR ANYTHING!!! I love the AK and it's cartridge. I just want people to understand how poorly it can perform with the wrong load.

Edited February 25, 2013 by Darth Saigus

[thebuns1 4,323]

While I do agree that some loads will perform better than others, I dont see this caliber being as ineffective as many may claim. I feel a well placed shot with one of the lower performing loads will offer better results than a poorly placed shot with a better performing bullet. I also feel that modern bullets will perform better than those from 40+ yrs ago. I dont want to see this thread turn into a pissing match, but bullet construction is vital to performance, regardless of caliber. And for the lack of terminal performance, I feel its a moot argument as any caliber will have its good and bad loads.

The lack of terminal performance is not a moot point if you are shooting a bad guy who's shooting at you.

 

Yes shot placement is important. It goes without saying that shot placement is important. Can we just agree to that and keep the thread focused on the original point?

 

And it is NOT a caliber vs caliber discussion. PLEASE, NO!

 

It is just me pointing out what I discovered about the x39 that others may find useful.

Well if your using shitty loads, then dont expect them to perform very good.

 

Ive seen firsthand what these rounds do to 300+lbs hogs. Its not pretty. I have no doubt of the effectiveness of the cartridge with good loads.

[Piratesailor 14]

Good read and I've been looking at 7.62, 5.45 and 5.56 recently on a variety of forums. I own several 7.62 saiga a so it's of interest to me

 

Darth, your observations and reading brings up good points. And it's not a caliber argument.

 

From what I can tell, it's a discussion about what to use at the right time; what is the best tool.

 

The only comment I'd have is that my "belief" is that in the case of the Stockton shooting, rifles at close range are not going to be effective in mass wound due to a lack of tumbling given the extreme short distance.

 

The only other comment would be "I'd hate to get hit by any of them"

 

 

[Spetnaz Soldier 47]

I have seen MANY discussions of 7.62x39 vs 5.56 and generally figured it boiled down to preference.

 

Recently I have been thinking more about the performance of different loads in each caliber. Not really one vs the other, but load vs load in the same caliber.

 

With my purchase of the M92PV which will eventually become my first SBR I have been reading everything I can find about the 7.62x39 out of short barrels.

 

In the end I can't say there is much real data out there on the subject. At least not published data.

 

One thing that I have found that startled me was just how INEFFECTIVE some 7.62x39 loads are. It can be summed up by these particular quotes from Dr Gary Roberts:

 

"WDMET (Wound Data and Munitions Effectiveness Team) collected extensive forensic data on over 700 7.62 x 39 mm gunshot wounds during the Viet Nam war. The predominant feature of this cartridge is the MINIMAL amount of damage it produces in soft tissue wounds, on par with FMJ handgun wounds such as those produced by 9 mm M882 ball."

 

"For example, in the 17 January 1988 Stockton school shooting, 30 of 35 kids who were shot lived. Of the five that died, all were shot in critical structure––head, heart, spine, aorta and none had damage to any organ not directly hit by a bullet."

 

This shows pitiful performance for a rifle cartridge. In both of the above cases, it was a blessing that it performed badly, but if you were to actually rely on an AK for defensive purposes it could get you killed. I find this unacceptable.

 

Some imported loads perform much better than others, but unless you have tested the particular lot of ammo you can't be sure because the foreign manufacturers are notorious for changing components. So Wolf Military Classic (which tests have shown to be a good performer) may not perform well if they change anything about the bullets.

 

This isn't a knock against the cartridge itself, or the rifles that use it. I am a kalashnikov fan from way back. Just a case of understanding the reality that all 7.62x39 ammo is not equal. This applies to 5.56mm as well.

 

The most consistent terminal performance is going to be from premium bullets which are designed to expand/fragment.

 

Just thought I'd share this. I assume many of you had already reached this obvious conclusion, but I know that there are lots of AK owners who don't know just how poorly this cartridge can perform with the wrong ammo.

Heres an idea. If you are depending on the ak to defend your self learn to be a good shot and get surgical with that shit. Dont shoot someone just wherever and hope it tumbles around and hits an artery...be a marksmen.

[Tool_of_Society 15]

I can tell you that a good SP load like Patizan PPU causes massive damage to hogs of all sizes.

[thebuns1 4,323]

Sorry Darth if my last post came off as a dick. I wasnt trying to be in any way dude.To me, when someone talks about the performance of a load, I take everything into consideration. Including the standard deviation, jacket separation, weight retention,as well as the ballistic coefficient to get a better idea of the overall balance that certain loads bring with it.

 

I can also understand where your coming from, as many people are sitting on a large sum of ammo that may be of the lower grade. Its nice to know how well it may or may not perform when you need it most.

[breid1970 327]

Not to be a prick, but using terminal ballistics from a school shooting may not be in our (the law biding honest citizens) best interest right now. Beside the fact that your quoting someone else it makes us look like gun toting lunatics. As for using the weapon, despite that we may or may not have "perfect" ammo, when in doubt do what the Marines have been teaching for the past twenty years. Two to the chest, one to the head. Its called the "failure to stop drill." I do not care one way what type of body armor your wearing. If getting shot in the face, does not put your target down. Throw poop in they're eyes. Trust me, the poop will be there at that point.

[SaigaKen 338]

Not to be a prick, but using terminal ballistics from a school shooting may not be in our (the law biding honest citizens) best interest right now. Beside the fact that your quoting someone else it makes us look like gun toting lunatics. As for using the weapon, despite that we may or may not have "perfect" ammo, when in doubt do what the Marines have been teaching for the past twenty years. Two to the chest, one to the head. Its called the "failure to stop drill." I do not care one way what type of body armor your wearing. If getting shot in the face, does not put your target down. Throw poop in they're eyes. Trust me, the poop will be there at that point.

Nice avatar....got a good version of that file?

[theorangeplanet 968]

You don't need hydrostatic shock to do lateral damage to organ structures. Energy is still transferred when the bullet is point forward, though not as much as sideways or expanding. Here is a graphic I made from screens of BrassFetcher's videos of the Wolf FMJ above and 9mm NATO. It demonstrates the temporary cavitation from each impact at its maximum upset.

 

 

From what I was able to extrapolate, with the 86% increase in velocity there was a about 66% increase in temporary cavitation in 7.62 over 9mm when measured before the 5 inch mark.

Edited February 25, 2013 by Risky

[breid1970 327]

Not to be a prick, but using terminal ballistics from a school shooting may not be in our (the law biding honest citizens) best interest right now. Beside the fact that your quoting someone else it makes us look like gun toting lunatics. As for using the weapon, despite that we may or may not have "perfect" ammo, when in doubt do what the Marines have been teaching for the past twenty years. Two to the chest, one to the head. Its called the "failure to stop drill." I do not care one way what type of body armor your wearing. If getting shot in the face, does not put your target down. Throw poop in they're eyes. Trust me, the poop will be there at that point.

Nice avatar....got a good version of that file?

Man I can not for the life of me remember where I got it. I think i just googled female russian soldiers. There were soooo many to choose from. Yuri Andropov would have been proud.

[Paulry 50]

Hey, check out this video where he chronographs the PAP 92

 

Edited February 26, 2013 by Fluid Power

[XD45 7,124]

I am only trying to move past the preconceptions and misconceptions and gain a better understanding of the reality.

 

My hope is that we can all gain a little knowledge. And knowledge is power.

 

Here is a long and detailed article about the 7.62x39, it's limitations, and it's real capability with modern ammunition.

 

http://demigodllc.com/articles/7.62x39-improving-the-military-standard/?p=1

Edited February 27, 2013 by Darth Saigus

[XD45 7,124]

Hey, check out this video where he chronographs the PAP 92

I have seen this video. It's very promising that the short barrel still gives over 2150 fps.

 

I intend to chrono a few different loads, and do some water jug testing with my new M92 soon.

Edited February 26, 2013 by Darth Saigus

[thebuns1 4,323]

That was a good read Darth. It kinda confirms what Ive been hinting at, but at the same time I was unaware of the ablility of the shorter barrels. Thats good to know. I find it interesting that they pointed out why many people look down on the cartridge, I feel with all the newer bullets coming out, we can expect some minds to rethink their previous accusations.

[breid1970 327]

I agree that there are some short comings with the current standard of ammunition, and that eventually we will get better loads, but my point is still valid. Especially with the present political climate.

[XD45 7,124]

I agree that there are some short comings with the current standard of ammunition, and that eventually we will get better loads, but my point is still valid. Especially with the present political climate.

We already have better loads. Hornady and Corbon both make loads with modern expanding bullets. I just ordered 800rds of the Hornady SST. The ZM is the same bullet with a green tip and juvenile graphics on the box.

 

It's more expensive of course. I won't be using it for practice when I can get the imported stuff less than half the price. But I'll run a couple hundred rounds to make sure it functions well.

 

That was a good read Darth. It kinda confirms what Ive been hinting at, but at the same time I was unaware of the ablility of the shorter barrels. Thats good to know. I find it interesting that they pointed out why many people look down on the cartridge, I feel with all the newer bullets coming out, we can expect some minds to rethink their previous accusations.

 

With a little knowledge of internal ballistics you can see that the 7.62x39 is at the extreme low end of the scale when it comes to case volume to bore area ratio. It almost seems like it was designed for short barrels from the start.

Edited February 27, 2013 by Darth Saigus

[thebuns1 4,323]

With a little knowledge of internal ballistics you can see that the 7.62x39 is at the extreme low end of the scale when it comes to case volume to bore area ratio. It almost seems like it was designed for short barrels from the start.

 

It does do rather well in short barrels vs. other calibers. Im more impressed with the modern bullets like the SST and Barnes offerings. Im a fan of the Hornady SST. Im curious to see how well it will do out of my new 20" bbl.

[mostholycerebus 415]

Wish I could find some Corbon MPG for sale somewhere. Then my AK would replace my HD shotgun.

[Remek 771]

Excellent read. Thanks!

[SaigaKen 338]

I agree that there are some short comings with the current standard of ammunition, and that eventually we will get better loads, but my point is still valid. Especially with the present political climate.

We already have better loads. Hornady and Corbon both make loads with modern expanding bullets. I just ordered 800rds of the Hornady SST. The ZM is the same bullet with a green tip and juvenile graphics on the box.

 

It's more expensive of course. I won't be using it for practice when I can get the imported stuff less than half the price. But I'll run a couple hundred rounds to make sure it functions well.

 

That was a good read Darth. It kinda confirms what Ive been hinting at, but at the same time I was unaware of the ablility of the shorter barrels. Thats good to know. I find it interesting that they pointed out why many people look down on the cartridge, I feel with all the newer bullets coming out, we can expect some minds to rethink their previous accusations.

 

With a little knowledge of internal ballistics you can see that the 7.62x39 is at the extreme low end of the scale when it comes to case volume to bore area ratio. It almost seems like it was designed for short barrels from the start.

 

Can you PM or add a link (if forum rules allow) for the expanding ammo you have?

[XD45 7,124]

Hornady SST. SGAmmo has it in stock every few days, but you have to be quick or you'll miss it.

 

http://www.hornady.com/store/7.62X39-123-gr-SST/

 

Here is a little extra data on the SST. According to what source you listen to, the minimum expansion velocity of the SST is 1600-1800fps, so until further testing I'll consider 1800fps to be the maximum effective range. YMMV.

 

Using a ballistic calculator and assuming a MV of 2,380fps:

 

Range Velocity Energy Trajectory

0 2380 1547 -1.5

25 2309 1456 0.1

50 2239 1369 1.3

75 2171 1287 2.0

100 2103 1208 2.3

125 2037 1133 2.1

150 1972 1062 1.3

175 1909 995 0.0 Zero Range

200 1847 931 -1.9

225 1786 871 -4.4

250 1726 814 -7.6

 

And from the 10.25" barrel of the PAP pistol/sbr:

 

0 2180 1298 -1.5

25 2112 1218 -0.4

50 2046 1143 0.3

75 1981 1072 0.4

100 1917 1004 0.0 Zero Range

125 1855 940 -1.0

150 1794 879 -2.7

175 1734 821 -5.0

200 1676 767 -8.0

Edited February 27, 2013 by Darth Saigus

[S12KS-K 40]

Pretty sure there's a reason the Soviets spent billions switching to the 5.45 but it's just a hunch..

[XD45 7,124]

Pretty sure there's a reason the Soviets spent billions switching to the 5.45 but it's just a hunch..

I thought it was because they wanted to be more like us.

[mostholycerebus 415]

I would think that as powder and bullet technology improves, x39 will become a more popular round again due to its ability to punch through cover, work well in more manuverable carbines, and launch a big bullet.

 

At this point, alot has been done with different bullet types and velocity through different barrel lengths. What I havent seen done is measuring accuracy at different barrel lengths. End user tales say that the Hungarian AMD65's 12.5" barrel is nearly as accurate as the russian 16", thoeretically due to reduced barrel whip. Finding the 'sweet spot' on the AK platform where we have manuverability, without sacrificing much velocity or accuracy, is the next breakthrough on this platform.

Pretty sure there's a reason the Soviets spent billions switching to the 5.45 but it's just a hunch..

Cheaper/easier to produce, better ballistics in FMJ, soldiers can carry more (not necessarily better) ammo?

 

A military makes its decisions for many reasons, few if any of which correspond to whats best for an individual civilians self defense. Wars are won by, and armies are run by, logistics and budgets. A soldiers rules are different from my rules. ANY assumed correspondence between the two should be thoroughly examined.

 

I dont go to the church of Gabe, but one thing he preaches that I agree with is, a soldier, or a cop, have far different assumptions, resources, and therefore tactics in the field compared to a civilian preparing for self, home, or national defense. We can pick any tools we choose, have different types of support, and are differently constrained in what actions we can legally take.

Edited February 28, 2013 by mostholycerebus

[XD45 7,124]

Just thought I'd add some more info to this thread that I've come across.

 

First a velocity chart of some common ammo types. Looks like GT is the shit for fmj.

 

 

And then there's this. Just because it's a soft point doesn't mean it will expand. Steel (bimetal) soft points will punch right through like a fmj. Keep that in mind.

 

http://www.youtube.com/watch?v=H6RVuISLJ3o

Edited August 12, 2013 by Darth Saigus

[Rhodes1968 1,638]

I keep a supply of Remington PSPs, those open.