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Posted: 10/9/2005 5:09:44 PM EDT
OK, for those of you who own AR15's and have been to the AR15 board I'm sure you are used to discussions about bullet ballistics and wound capability. If you are not familiar with such discussions regarding the 5.56mm X 45mm round, you should read up about it. There's been a long running debate on the NATO rounds effectiveness when shot out of a short (under 16") barrel, and its ability to fragment like it was designed to do.

But the 7.62mm X 39mm round is a different animal entirely. The bullet was designed as a traditional FMJ mid range rifle round, and while there is a chance for 7.62mm rounds to fragment (GOOD rounds, not el'cheapo ones)the 7.62 relies on the bullets ability to yaw (turn & tumble) after hitting soft tissue. Of course this is old news to the Guru's here, but I got to thinking:

Alot of people consider the 7.62mm round as being under-powered, well, as far as battle rifle rounds are concerned anyway. But after thinking about it, I think this may be why the round has enjoyed the success that it has over the last 1/2 century.  IF the round was a super high velocity round like the 5.56mm NATO round is it would probably just punch right through soft tissue, not creating any collateral damage on surrounding tissue, thus leaving only clean .30 cal holes...that is...unless the bullet can be made to yaw earlier. But the 7.62mm round isn't a high velocity round.

Hypothetically speaking at battle distances (90 - 200meters) the Russian round is more than a capable battle round, at least in my opinion regardless if it is an obsolete round or not. It has just the right energy to propell it's 125gr round enough to neutralize enemy personel by transferring it's energy within the target without passing through. At first the seeming lack luster power of the Russian round acutally turns out in the bullets ballistic favor...especially out of SHORTER BARRELS. This is where the round peaked my interest.

I have a thing for Carbines. Carbines are COOL. They offer suprerior manuverability to full sized rifles all while offering much more powerful rounds than those chambered in most service pistols, not to mention the added accuracy over a handgun they offer. It's a well known fact that AR15's make crappy carbines when chambered in 5.56mm. The shorter barrels simply can't produce the velocity needed in order for the NATO round to work.  HOWEVER the Kalashnikov design  chambered in 7.62mm has no such problem. It's round is 150% heavier than the XM193 that won't pass completely through an enemies body. thus ALLOWING THE IMPACT SHOCK TO REMAIN IN THE TARGET.  If anything, the lower velocity from being shot through a short barrel will cause the bullet to tumble sooner as it loses energy after entering the target, or at least in theory it would, keeping the energy inside that target.

Is this line of thinking way off? I have always favored .30 caliber rounds. Their size and weight alone have a potential to cause damage. Short barrel, long barrel, and everything inbetween. It's my humble opinion that a carbine such as a Krinkov chambered in 7.62mm is  a superior CQB weapon compared to a 10" barreled CAR15 or even an AR15 pistol for the soul fact that these weapons barrel are too short to cause their rounds to fragment. Yes, the SBR AR's are still potentially lethal even if they don't fragment rounds. A bullet is a bullet, and any bullet through a major organ will eventually stop an enemy. But if all you plan on inflicting is a hole (No temprary cavity) Bigger IS better. A .30 cal hole will cause more damage than a .22.

The 7.62mm round reminds me alot of another favorite caliber of mine: the .30 caliber Carbine. Both fit the ballistic niche' right between handgun loads and high powered rifle rounds: again, I think this is ideal for CQB and defensive work. The old 7.62mm round may be considered obsolete, but that doesn't mean it doesn't have its good points.
Link Posted: 10/9/2005 5:17:47 PM EDT
[Last Edit: 10/9/2005 5:24:11 PM EDT by clange]

Is this line of thinking way off?

Well, why do you think 7.62x39, even out of a short barrel, wouldnt pass through? Some old test i saw of it had a lot of penetration, and it yaws relatively late, unlike 5.45 which can be sideways in as little as 9-10cm. Most often the 7.62x39 probably does just punch a .30cal hole through someone. I've seen it on a deer when i screwed up and used FMJ. Tiny hole on both sides.

I dont know if less velocity would make it yaw quicker or not, since there havent been any tests (that i've seen) of 7.62x39 (or 5.45) out of a short barrel.
Link Posted: 10/9/2005 5:19:09 PM EDT
Thank you, I now have a headache.
Link Posted: 10/9/2005 5:24:55 PM EDT
anyone want to volunteer to be my test target for my underpowered 7.62x39?
Link Posted: 10/9/2005 5:30:37 PM EDT
[Last Edit: 10/9/2005 5:34:41 PM EDT by Atreides]
The bullet design of the 7.62mm is the reason why it has such deep penetration, and why the bullet does not yaw earlier. With less velocity the bullet will be prone to yaw earlier: therefore causing more damage. Again, in theory. The lead core bullets more so than the old steel cores I'd think.

The bullet is, as I have said, old technology: it is a text book FMJ cartridge round. Keep in mind when it was designed: back in the days before hyper expanding and fragmenting rounds, yet, it is a proven performer.

Hey darkness, if you READ the post you'd know it praises the 7.62 round for what it is, not critisize it.
Link Posted: 10/9/2005 5:33:48 PM EDT
IIRC the 7.62x39 round is inherently a very accurate round.  More so than the 5.56 if i'm not mistaken.
Link Posted: 10/9/2005 5:37:25 PM EDT
[Last Edit: 10/9/2005 5:40:12 PM EDT by Atreides]
Maybe so .45, but for accuracy I personally choose the 5.56mm over 7.62 anyday, especially with targets 75yrds and above. For CQB distances however accuracy difference between the 2 is moot.

Again, this is my choice. I can shoot my 14.5" barrel AR15 alot more accurately than my 20" SKS. Maybe it's a gun design difference and not a bullet difference.
Link Posted: 10/9/2005 5:37:31 PM EDT
[Last Edit: 10/9/2005 5:39:04 PM EDT by clange]

Originally Posted By Atreides:
The bullet design of the 7.62mm is the reason why it has such deep penetration, and why the bullet does not yaw earlier. With less velocity the bullet will be prone to yaw earlier: therefore causing more damage.


Again, what are you basing this on? Doesnt 5.56 fragment, because it yaws? Same with 5.45, the high speed and sudden change in density causes it to quickly yaw (along with the weight bias to the rear). Its possible that less velocity could cause it to yaw less. You cant really say for sure without tests of the rounds out of shorter barrels.
Link Posted: 10/9/2005 5:40:14 PM EDT
I can definitely see where you are coming from.  The ballistics of a Krinkov in 7.62 would be superior to an M4 style carbine with a barrel shorter than 10 inches.

The problem that is see is this.  With a CQB-R and M855, I have almost no recoil.  The last Krink in 7.62 that I handled as an anti aircraft gun.  For me, being able to put the rounds right on target is the most important aspect of the wewapon system.

Furthermore, rounds such as the 5.45 and 5.56 with Hornady AMX promise to turn sideways and deliver a larger wound than M855 would.  I like this idea a lot.  A 10.5 M4 is roughly the same length as a Krink.  With MK262 it will fragment to approx 40 yards, according to our resident ammo experts.  A source I spoke with assured me that M855 will fragment at CQB ranges in barrels as short as 9 inches.  Don't ask who or how, I can't say.

So while I am in a manner of agreement with you, under certain circumstances, I feel in no way undergunned with a short M4.  I would like to thank fizzasit, among others, for helping me realize the effectiveness of shorties.

BTW, the rounds that the Iraqi's use do fragment.  Also, a JHP in 7.62 would probably increase lethality by leaps and bounds.  I know that it does that for .30 M1 Carbine.
Link Posted: 10/9/2005 5:43:05 PM EDT

Originally Posted By FortyFiveAutomatic:
IIRC the 7.62x39 round is inherently a very accurate round.  More so than the 5.56 if i'm not mistaken.



I don't know about that.  Cartidges with less body taper tend to be more accurate.  I think it ould be great to Ackley Improve the 7.62 for hunting and other sport uses.  For one thing, you could use 20 round USGI mags in an AR.  Best of both worlds.
Link Posted: 10/9/2005 5:47:01 PM EDT
[Last Edit: 10/9/2005 6:03:47 PM EDT by Atreides]

Originally Posted By clange:

Originally Posted By Atreides:
The bullet design of the 7.62mm is the reason why it has such deep penetration, and why the bullet does not yaw earlier. With less velocity the bullet will be prone to yaw earlier: therefore causing more damage.


Again, what are you basing this on? Doesnt 5.56 fragment, because it yaws? Same with 5.45, the high speed and sudden change in density causes it to quickly yaw (along with the weight bias to the rear). Its possible that less velocity could cause it to yaw less. You cant really say for sure without tests of the rounds out of shorter barrels.



Both the 5.56mm and the 5.45mm bullet is designed to Yaw. The "boat-tail" design causes the round to tumble BUT in the case of the 5.56mm round a minimal velocity of 2700 fps in needed to initiate yaw once the bullet enters soft tissue. Without this speed, the bullet is prone to punch right through. In the case of older designed bullets, it's resistance that initiate yaw, NOT bullet design (well not entirely). As the bullet loses energy, it also loses the ability to maintain a straight tragectory. The 7.62mm round tends to track straight initially and only begin to tumble after it begins to lose energy, it is a good example of older bullet ballistics.

As for "TESTS" well to get an understanding how a bullets characteristics can change due to barrel length I suggest reading this: http://www.ammo-oracle.com/body.htm
Link Posted: 10/9/2005 5:52:21 PM EDT
[Last Edit: 10/9/2005 5:54:40 PM EDT by Atreides]

Originally Posted By Combat_Jack:
I can definitely see where you are coming from.  The ballistics of a Krinkov in 7.62 would be superior to an M4 style carbine with a barrel shorter than 10 inches.

The problem that is see is this.  With a CQB-R and M855, I have almost no recoil.  The last Krink in 7.62 that I handled as an anti aircraft gun.  For me, being able to put the rounds right on target is the most important aspect of the wewapon system.

Furthermore, rounds such as the 5.45 and 5.56 with Hornady AMX promise to turn sideways and deliver a larger wound than M855 would.  I like this idea a lot.  A 10.5 M4 is roughly the same length as a Krink.  With MK262 it will fragment to approx 40 yards, according to our resident ammo experts.  A source I spoke with assured me that M855 will fragment at CQB ranges in barrels as short as 9 inches.  Don't ask who or how, I can't say.

So while I am in a manner of agreement with you, under certain circumstances, I feel in no way undergunned with a short M4.  I would like to thank fizzasit, among others, for helping me realize the effectiveness of shorties.

BTW, the rounds that the Iraqi's use do fragment.  Also, a JHP in 7.62 would probably increase lethality by leaps and bounds.  I know that it does that for .30 M1 Carbine.



Great points Jack.

It's about time someone produced fragmenting 7.62mm bullets. the old designed ones wouldn't. Too thick jacketing, long bodies, with not enough power.

I hear what your saying about the M4 too Jack, and I agree with you. I wouldn't feel out gunned either. Like I said, a bullet is a bullet, and even IF the 5.56 didn't blow up like it should, a centermass shot or 2 will still do the job. Maybe not as fast as the same bullet out of a 20" AR, but it would still work.

Speaking of M1 Carbines, even SOFT POINTS improve ballistics alot. I know they'll put a Hog down way easier than an FMJ ball that's for sure.
Link Posted: 10/9/2005 6:05:44 PM EDT
There are some inaccuracies here.  A bullet yaws when the center of gravity is behind the center of the bullet.  Think of a badmitten shuttle cock.  The weight is forward so it is stable.  A bullet with the center of gravity to the rear is inherently unstable.  But the spin means it can't yaw and tumble in flight.  If the spin is insufficient to stabilize the bullet, it will yaw and tumble in flight.  

When the bullet enters a denser medium, the spin rate that stabilizes it in air is no longer sufficient to stabilize it in the denser medium, i.e. flesh.  How quickly it starts to yaw is dependent on the bullet construction and spin.   Bullet fragmentation is dependent upon sufficient stress to overcome the tensile strength of the jacket.  Tensile strength is dependent upon the jacket material and thickness and any defects in the jacket, intentional or not.  5.56mm fails at the cannelure because this "defect" creates a weak point in the jacket.  West German 7.62x51 had a thin, brittle jacket and it will fragment like 5.56.  That is a really nasty round.  Velocity is the other factor that stresses the jacket.  If the bullet is moving fast enough, when the bullet yaws the forces can exceed the tensile strength of the jacket.  With 55gr and 62gr 5.56mm bullets, that velocity threshold is approximately 2700fps.  A short barrelled M16/M4 can be effective, but fragmentation distance is pretty short.  After that, it will tumble, but not fragment.

7.62x39 is a blunter, shorter round compared to the 5.56mm or 5.45mm.  Consequently, it is not as unstable and it penetrates deeper before it yaws.  I believe it is Yugoslavian ammo that has a brittle jacket and will fragment, but I may be mistaken on that one.  Most of the others don't create enough stress to make the bullet fragment.  Remember, when you are comparing a 5.56mm to a 7.62mm projectile, the 5.56 is a lot longer in comparison to its diameter than the 7.62 and therefore the stresses will be greater when it yaws.
Link Posted: 10/9/2005 6:06:17 PM EDT
BTW, the 7.62x39mm in ballistic gelatin essentially replicates the performance of .38 Special, a round not known for its superior terminal effectiveness. The .38 enters, yaws and leaves base first. Marshall and Sanow rate that caliber at 50%. So even they do't like it.

However, there is no denying that a LOT of people have been killed with that caliber.

Also, energy transfer is BS. All that matters as a wounding mechanism is the amount and type of destroyed and damaged tissue, the amount of blood loss, etc.
Link Posted: 10/9/2005 6:08:30 PM EDT
[Last Edit: 10/9/2005 6:10:18 PM EDT by clange]

I hear what your saying about the M4 too Jack, and I agree with you. I wouldn't feel out gunned either. Like I said, a bullet is a bullet, and even IF the 5.56 didn't blow up like it should, a centermass shot or 2 will still do the job. Maybe not as fast as the same bullet out of a 20" AR, but it would still work.

But what hes saying is that at CQB distances, like shooting across a room, it will still fragment out of short barrels.


Both the 5.56mm and the 5.45mm bullet is designed to Yaw. The "boat-tail" design causes the round to tumble BUT in the case of the 5.56mm round a minimal velocity of 2700 fps in needed to initiate yaw once the bullet enters soft tissue. Without this speed, the bullet is prone to punch right through. In the case of older designed bullets, it's resistance that initiate yaw, NOT bullet design (well not entirely). As the bullet loses energy, it also loses the ability to maintain a straight tragectory.

Every bullet thats pointed at the front and wide at the back will yaw, that doesnt mean they were designed to do so. The 5.56, as far as i understand it, fragments because it yaws and cant handle the stress. The velocity level is where it cant handle going sideways, not the velocity it needs to yaw since it will do that anyway. At lower velocity it may yaw sooner or later, i dont know, but it wont be blown apart by the stress since its moving slower. Edit: Beaten by dorsai

You may be right about the older bullet like 7.62 yawing more quickly if moving slower. If so i'd think it would be as effective, or more out of a short barrel, to a certain distance where it still retains velocity to penetrate.

In any case, using soft point would quickly negate all this FMJ talk.
Link Posted: 10/9/2005 6:09:00 PM EDT
[Last Edit: 10/9/2005 6:25:32 PM EDT by Atreides]

Originally Posted By Dorsai:
There are some inaccuracies here.  A bullet yaws when the center of gravity is behind the center of the bullet.  Think of a badmitten shuttle cock.  The weight is forward so it is stable.  A bullet with the center of gravity to the rear is inherently unstable.  But the spin means it can't yaw and tumble in flight.  If the spin is insufficient to stabilize the bullet, it will yaw and tumble in flight.  

When the bullet enters a denser medium, the spin rate that stabilizes it in air is no longer sufficient to stabilize it in the denser medium, i.e. flesh.  How quickly it starts to yaw is dependent on the bullet construction and spin.   Bullet fragmentation is dependent upon sufficient stress to overcome the tensile strength of the jacket.  Tensile strength is dependent upon the jacket material and thickness and any defects in the jacket, intentional or not.  5.56mm fails at the cannelure because this "defect" creates a weak point in the jacket.  West German 7.62x51 had a thin, brittle jacket and it will fragment like 5.56.  That is a really nasty round.  Velocity is the other factor that stresses the jacket.  If the bullet is moving fast enough, when the bullet yaws the forces can exceed the tensile strength of the jacket.  With 55gr and 62gr 5.56mm bullets, that velocity threshold is approximately 2700fps.  A short barrelled M16/M4 can be effective, but fragmentation distance is pretty short.  After that, it will tumble, but not fragment.

7.62x39 is a blunter, shorter round compared to the 5.56mm or 5.45mm.  Consequently, it is not as unstable and it penetrates deeper before it yaws.  I believe it is Yugoslavian ammo that has a brittle jacket and will fragment, but I may be mistaken on that one.  Most of the others don't create enough stress to make the bullet fragment.  Remember, when you are comparing a 5.56mm to a 7.62mm projectile, the 5.56 is a lot longer in comparison to its diameter than the 7.62 and therefore the stresses will be greater when it yaws.



Thanks Dorsai!

I failed to bring up jacket thinkmess when discussing newer bullet design. Of course you are absolutely correct.

Again, it is the difference between older bullet designs, and more modern ones. The 7.62mm X 39 was designed right before bullet design began to change into the modern era.

But I believe this works in the &.62mm's favor when used in short barreled rifles. Heavy large caliber MID-range bullets seem ideal for an SBR in my opinion. Just enough power for CQB situations with the punch of a rifle round.
Link Posted: 10/9/2005 6:15:18 PM EDT

Originally Posted By clange:

I hear what your saying about the M4 too Jack, and I agree with you. I wouldn't feel out gunned either. Like I said, a bullet is a bullet, and even IF the 5.56 didn't blow up like it should, a centermass shot or 2 will still do the job. Maybe not as fast as the same bullet out of a 20" AR, but it would still work.

But what hes saying is that at CQB distances, like shooting across a room, it will still fragment out of short barrels.


Both the 5.56mm and the 5.45mm bullet is designed to Yaw. The "boat-tail" design causes the round to tumble BUT in the case of the 5.56mm round a minimal velocity of 2700 fps in needed to initiate yaw once the bullet enters soft tissue. Without this speed, the bullet is prone to punch right through. In the case of older designed bullets, it's resistance that initiate yaw, NOT bullet design (well not entirely). As the bullet loses energy, it also loses the ability to maintain a straight tragectory.

Every bullet thats pointed at the front and wide at the back will yaw, that doesnt mean they were designed to do so. The 5.56, as far as i understand it, fragments because it yaws and cant handle the stress. The velocity level is where it cant handle going sideways, not the velocity it needs to yaw since it will do that anyway. At lower velocity it may yaw sooner or later, i dont know, but it wont be blown apart by the stress since its moving slower.

You may be right about the older bullet like 7.62 yawing more quickly if moving slower. If so i'd think it would be as effective, or more out of a short barrel, to a certain distance where it still retains velocity to penetrate.

In any case, using soft point would quickly negate all this FMJ talk.




I disagree clange. A 5.56 will NOT fragment out of a short barrel any better at close range than it would at distance. Velocity causes the bullet to break up, and without it all the bullet will do at best is yaw: NOT Fragment.

The Boat-tail design is not simply a bullet that is wider in the rear than it is in the front. A boat tail carries most of its mass in the rear, where as a 7.62 carries it's weight more uniformly through out the bullets body (More balance). There IS a HUGE difference in bullet design my friend.
Link Posted: 10/9/2005 6:27:21 PM EDT
[Last Edit: 10/9/2005 6:31:16 PM EDT by clange]

Originally Posted By Atreides:

Originally Posted By clange:

I hear what your saying about the M4 too Jack, and I agree with you. I wouldn't feel out gunned either. Like I said, a bullet is a bullet, and even IF the 5.56 didn't blow up like it should, a centermass shot or 2 will still do the job. Maybe not as fast as the same bullet out of a 20" AR, but it would still work.

But what hes saying is that at CQB distances, like shooting across a room, it will still fragment out of short barrels.


Both the 5.56mm and the 5.45mm bullet is designed to Yaw. The "boat-tail" design causes the round to tumble BUT in the case of the 5.56mm round a minimal velocity of 2700 fps in needed to initiate yaw once the bullet enters soft tissue. Without this speed, the bullet is prone to punch right through. In the case of older designed bullets, it's resistance that initiate yaw, NOT bullet design (well not entirely). As the bullet loses energy, it also loses the ability to maintain a straight tragectory.

Every bullet thats pointed at the front and wide at the back will yaw, that doesnt mean they were designed to do so. The 5.56, as far as i understand it, fragments because it yaws and cant handle the stress. The velocity level is where it cant handle going sideways, not the velocity it needs to yaw since it will do that anyway. At lower velocity it may yaw sooner or later, i dont know, but it wont be blown apart by the stress since its moving slower.

You may be right about the older bullet like 7.62 yawing more quickly if moving slower. If so i'd think it would be as effective, or more out of a short barrel, to a certain distance where it still retains velocity to penetrate.

In any case, using soft point would quickly negate all this FMJ talk.




I disagree clange. A 5.56 will NOT fragment out of a short barrel any better at close range than it would at distance. Velocity causes the bullet to break up, and without it all the bullet will do at best is yaw: NOT Fragment.

The Boat-tail design is not simply a bullet that is wider in the rear than it is in the front. A boat tail carries most of its mass in the rear, where as a 7.62 carries it's weight more uniformly through out the bullets body (More balance). There IS a HUGE difference in bullet design my friend.


1) 5.56 has velocity sufficient to fragment at those distances, as others have mentioned, even out of a short barrel. You just said the exact same thing i said, at low velocity it will yaw but not fragment (originally you said it would go straight through), but what you havent acknowledged is that it will fragment at close distances out of a short barrel. If it didnt it wouldnt be popular for such uses. Yes, is does fragment better at close distance as opposed to farther out, this is why velocity is important because at a certain distance it doesnt have enough velocity to fragment.

2) 7.62x39 is still weight biased to the rear, and does yaw, albeit slowly like i said in my first post. Not sure where you're going with this, as its somewhat contrary to your point about 7.62 quickly yawing and staying in the body. Its either good at it or it isnt.
Link Posted: 10/9/2005 6:30:57 PM EDT

Originally Posted By FortyFiveAutomatic:
IIRC the 7.62x39 round is inherently a very accurate round.  More so than the 5.56 if i'm not mistaken.



That's incorrect. The 5.56 is the more accurate of the round.

Listen to guys who shoot 5.56 AKs compared to 7.62 AKs.

The accuracy is increased when shooting the AR system of rifles. IT is inherently more accurate than the AK ...just designed that way.
Link Posted: 10/9/2005 6:35:25 PM EDT
[Last Edit: 10/9/2005 6:53:00 PM EDT by JaketheSnake]

Originally Posted By clange:

Originally Posted By Atreides:

Originally Posted By clange:

I hear what your saying about the M4 too Jack, and I agree with you. I wouldn't feel out gunned either. Like I said, a bullet is a bullet, and even IF the 5.56 didn't blow up like it should, a centermass shot or 2 will still do the job. Maybe not as fast as the same bullet out of a 20" AR, but it would still work.

But what hes saying is that at CQB distances, like shooting across a room, it will still fragment out of short barrels.


Both the 5.56mm and the 5.45mm bullet is designed to Yaw. The "boat-tail" design causes the round to tumble BUT in the case of the 5.56mm round a minimal velocity of 2700 fps in needed to initiate yaw once the bullet enters soft tissue. Without this speed, the bullet is prone to punch right through. In the case of older designed bullets, it's resistance that initiate yaw, NOT bullet design (well not entirely). As the bullet loses energy, it also loses the ability to maintain a straight tragectory.

Every bullet thats pointed at the front and wide at the back will yaw, that doesnt mean they were designed to do so. The 5.56, as far as i understand it, fragments because it yaws and cant handle the stress. The velocity level is where it cant handle going sideways, not the velocity it needs to yaw since it will do that anyway. At lower velocity it may yaw sooner or later, i dont know, but it wont be blown apart by the stress since its moving slower.

You may be right about the older bullet like 7.62 yawing more quickly if moving slower. If so i'd think it would be as effective, or more out of a short barrel, to a certain distance where it still retains velocity to penetrate.

In any case, using soft point would quickly negate all this FMJ talk.




I disagree clange. A 5.56 will NOT fragment out of a short barrel any better at close range than it would at distance. Velocity causes the bullet to break up, and without it all the bullet will do at best is yaw: NOT Fragment.

The Boat-tail design is not simply a bullet that is wider in the rear than it is in the front. A boat tail carries most of its mass in the rear, where as a 7.62 carries it's weight more uniformly through out the bullets body (More balance). There IS a HUGE difference in bullet design my friend.


1) 5.56 has velocity sufficient to fragment at those distances, as others have mentioned, even out of a short barrel. You just said the exact same thing i said, at low velocity it will yaw but not fragment (originally you said it would go straight through), but what you havent acknowledged is that it will fragment at close distances out of a short barrel. If it didnt it wouldnt be popular for such uses. Yes, is does fragment better at close distance as opposed to farther out, this is why velocity is important because at a certain distance it doesnt have enough velocity to fragment.

2) 7.62x39 is still weight biased to the rear, and does yaw, albeit slowly like i said in my first post. Not sure where you're going with this, as its somewhat contrary to your point about 7.62 quickly yawing and staying in the body. Its either good at it or it isnt.



Ammo Oracle Fragmentation
Great now I'm started to get confused?

The website talks about the effectiveness of the NATO 7.62 round vs the 5.56 NATO.
Basically.... the NATO 7.62 round is better at penetration on harder targets, like metal, even armor I suppose.
5.56 can penetrate armor as well, but is basically designed as a people killer. Soft tissue is the perfered target with the round. Granted any bullet would cause trauma on human tissue. The 5.56 just excells at it.

I'm still confused as to where you're going with this? Are you saying that a short krinkov type AK in 7.62 would be better than a short 10.5 AR? With both guns, I would say they are most likely going to be used in Close Quarters most likely in Fully Automatic. In that case I would have to give the AR the advantage as you would be able to control it better in full auto and make mag changes quicker. In Close Quarter combat I doubt fragmentation makes much of a difference. Especially when accurate volumes of firepower are employed.

I still may be crazy but I think a great CQB rifle would be this
Link Posted: 10/9/2005 6:42:18 PM EDT
[Last Edit: 10/9/2005 6:51:04 PM EDT by Atreides]
The 7.62 will consistantly start to yaw at the end of it's tragectory through a soft target. Yes, it is heavier in it's rear than it is in its front, but as rifle rounds go it is much more balanced than, lets say the 5.56 or .308. It begins to yaw as it loses energy, hence the "late" tumbling characteristic of the round.

I suggest reading the Ammo Oracle.


But what hes saying is that at CQB distances, like shooting across a room, it will still fragment out of short barrels.


Again, the 5.56mm bullet was designed as a battle round, NOT a CQB bullet. IT WILL NOT FRAGMENT any better at close range if it doesn't have the velocity to do so. Distance doesn't change anything, not ballistically anyway. Out of a 16" barrel? Sure, the 5.56mm WILL fragment at 10 feet, it'll also fragment just as much at a 100 feet.

BARREL LENGTH EFFECTS BULLET VELOCITY.

Short barrels cannot build enough chamber pressure to propel the bullet to terminal velocity before the bullet is released. The LONGER a barrel is, the more pressure can be build before the bullet leaves it.

A quote from the Ammo-Oracle:


The primary wounding mechanism for .223 and 5.56 ammunition is fragmentation. The primary factor in fragmentation is velocity. The primary velocity booster is barrel length. 11.5" barrels barely bring milspec (NATO) 55 grain FMJ to 2700 fps (the critical fragmentation threshold for many FMJ .223 rounds). Accordingly, any distance at all drops the rounds below fragmentation velocity. 10" barrels are unlikely to ever get rounds above fragmentation velocity at all.

Link Posted: 10/9/2005 6:44:49 PM EDT

Originally Posted By Atreides:
The Boat-tail design is not simply a bullet that is wider in the rear than it is in the front. A boat tail carries most of its mass in the rear, where as a 7.62 carries it's weight more uniformly through out the bullets body (More balance). There IS a HUGE difference in bullet design my friend.



Boat tails actually carry less of their mass to the rear than similarly styled flat base bullets. Bullets with open/hollow tips carry their mass to the rear. This has been found to be more accurate, hence the use of this design in match bulets. They also yaw more quickly--case in point: the 5.45mm. Boat tails are not used in benchrest shooting at 200 yards because the flat base bullets tend to be more accurate. This is hardly a concern for anyone else, and IMHO the increase in BC of the boattail is worth it for practical shooters.

The 7.62x39 M43 is a 300 yard cartridge. It has a rainbow of a trajectory. Thats fine, for its intended purpose.
Link Posted: 10/9/2005 6:46:35 PM EDT

Originally Posted By Atreides:
The 7.62 will consistantly start to yaw at the end of it's tragectory through a soft target. Yes, it is heavier in it's rear than it is in its front, but as rifle rounds go it is much more balanced than, lets say the 5.56 or .308. It begins to yaw as it loses energy, hence the "late" tumbling characteristic of the round.

I suggest reading the Ammo Oracle.


But what hes saying is that at CQB distances, like shooting across a room, it will still fragment out of short barrels.


Again, the 5.56mm bullet was designed as a battle round, NOT a CQB bullet. IT WILL NOT FRAGMENT any better at close range if it doesn't have the velocity to do so. Distance doesn't change anything, not ballistically anyway. Out of a 16" barrel? Sure, the 5.56mm WILL fragment at 10 feet, it'll also fragment just as much at a 100 feet.

BARREL LENGTH EFFECTS BULLET VELOCITY.

Short barrels cannot build enough chamber pressure to propel the bullet to terminal velocity before the bullet is released. The LONGER a barrel is, the more pressure can be build before the bullet leaves it.



His mention of distance ackknowledges velocity. He is saying that at short range, before it slows significantly, there is enough velocity to cause fragmentation.
Link Posted: 10/9/2005 6:48:03 PM EDT
[Last Edit: 10/9/2005 6:54:47 PM EDT by clange]

Again, the 5.56mm bullet was designed as a battle round, NOT a CQB bullet. IT WILL NOT FRAGMENT any better at close range if it doesn't have the velocity to do so. Distance doesn't change anything, not ballistically anyway. Out of a 16" barrel? Sure, the 5.56mm WILL fragment at 10 feet, it'll also fragment just as much at a 100 feet.

You're arguing semantics now, as you originally did not say "when it has the velocity to do so". All you said is "distance doesnt matter", and it most certainly does. You were talking about a certain case where it leaves the barrel below the velocity required to fragment. Of course, then it would never fragment. If it leaves the barrel slightly above the limit then distance does matter a great deal, because it can still fragment at 'other side of the room' distance, but it wont at 50 yards.

We're on the same page there.

According to the AR guys 5.56 WILL fragment out of a short barrel at close distance. If you dont agree with that i'll let them carry on the discussion with you because i am by no means an AR expert.
Link Posted: 10/9/2005 6:56:10 PM EDT
[Last Edit: 10/9/2005 6:58:10 PM EDT by Atreides]

Originally Posted By clange:

Again, the 5.56mm bullet was designed as a battle round, NOT a CQB bullet. IT WILL NOT FRAGMENT any better at close range if it doesn't have the velocity to do so. Distance doesn't change anything, not ballistically anyway. Out of a 16" barrel? Sure, the 5.56mm WILL fragment at 10 feet, it'll also fragment just as much at a 100 feet.

You're arguing semantics now, as you originally did not say "when it has the veolocity to do so". All you said is "distance doesnt matter", and it most certainly does. You were talking about a certain case where it leaves the barrel below the velocity required to fragment. Of course, then it would never fragment. If it leaves the barrel slightly above the limit then distance does matter a great deal, because it can still fragment at 'other side of the room' distance, but it wont at 50 yards.

We're on the same page there.

According to the AR guys 5.56 WILL fragment out of a short barrel at close distance. If you dont agree with that i'll let them carry on the discussion with you because i am by no means an AR expert.



You said SHORT BARREL. A SHORT BARREL will NOT produce enough Velocity to fragment. You also said that the 5.56 would fragment at close range regardless of barrel length.

My statement of Velocity doesn't matter was in reference to Short Barreled Rifles. A barrel is only capable of projecting a bullet as fast as it's pressure allows. A short barrel will have no more fragmenting ability at 10 than it would at 20 or 30.
Link Posted: 10/9/2005 7:00:06 PM EDT
I am surprised that any of you expect a balanced discussion considering the fact that this thread was posted in AK Discussions.
Link Posted: 10/9/2005 7:12:07 PM EDT
Problem is, there's no overwhelming domestic support for the cartridge.  Choices are bottom of the line as far as quality as compared to the super gee-whiz gofast shit that comes out daily for 5.56, etc.

I don't reload, so I really have no idea of the difficulties involved, but I have a feeling that if as much effort was put into load development for x39 as has been for 5.56, we'd see a far more impressive beastie.
Link Posted: 10/9/2005 7:13:05 PM EDT
How short of a short barreled rifle are we talking about?
Link Posted: 10/9/2005 7:13:11 PM EDT
.

I still may be crazy but I think a great CQB rifle would be this
img138.imageshack.us/img138/7708/fnminimispw5az.jpg


I LOVE YOUR CHOICE JAKE!
Link Posted: 10/9/2005 7:14:07 PM EDT

Originally Posted By Atreides:
.

I still may be crazy but I think a great CQB rifle would be this
img138.imageshack.us/img138/7708/fnminimispw5az.jpg


I LOVE YOUR CHOICE JAKE!



Eh. Fun, good for military CQB, but the neighbors would hate it.
Link Posted: 10/9/2005 7:14:32 PM EDT
[Last Edit: 10/9/2005 7:15:21 PM EDT by Atreides]

Originally Posted By Combat_Jack:
How short of a short barreled rifle are we talking about?



Like the Krinks 8.5" or 10" barrels Jack.

As for snakes choice....SCREW THE NEIGHBORS!!!! LOL!
Link Posted: 10/9/2005 7:23:00 PM EDT

Originally Posted By Atreides:

Originally Posted By Combat_Jack:
How short of a short barreled rifle are we talking about?



Like the Krinks 8.5" or 10" barrels Jack.

As for snakes choice....SCREW THE NEIGHBORS!!!! LOL!



10" AR barrels can frag.
Link Posted: 10/9/2005 7:36:20 PM EDT
The reason for my initial post was made because of my newfound ownership of a Krinkov Carbine. I used to think of the 7.62 X 39 as just another antique round, especially since I am a so called "AR15 Man".  But then I finally succumed to the fact that my beloved 5.56mm round (namely the XM193) sucked out of a short barrel. Like I said, I love my Carbines.

The Krinkov (Yugo) began to make sense to me. Especially when considering a gun for defensive use, and so did the 7.62mm round as well. I will still grab one of my trusty AR's if ever the SHTF (sorry AK dudes) but for up close stuff? I would far rather have this Krink in hand than a 7.5" AR pistol or 11.5" CAR15.

For me, it's about consistancy. While I really love my 7.5" Bushy, it cannot be relied upon to fragment it's rounds. On the other hand I have the Krink: Bigger Bullet, Bigger Holes. Nothing fancy. Just a bigger bullet that will perform like it was designed to do.

I mentioned my M1 Carbine earlier. It is possibly my most treasured gun I own right now. It's OLD...it uses obsolete ammo. But it is one of the most balanced weapons I have ever owned. The only drawback the gun had for use as a defense gun was its 18.5" barrel length. Now I have a gun with comparable ballistics with a 16" barrel. (Muzzle device attached). Still the gun is compact in comparison.

The Krink makes more sense to me as a CQB than an AR15 with the same barrel length. Of course we would be talking apples and oranges once the barrel length got up to 16" and above. The Kalashnikov design has been gaining favor on me recently however and I have become very appreciative of the weapons design and ruggedness. I will soon be adding a couple of rifle length ones to my collecting for sure.
Link Posted: 10/9/2005 7:41:05 PM EDT

Originally Posted By Combat_Jack:

Originally Posted By Atreides:

Originally Posted By Combat_Jack:
How short of a short barreled rifle are we talking about?



Like the Krinks 8.5" or 10" barrels Jack.

As for snakes choice....SCREW THE NEIGHBORS!!!! LOL!



10" AR barrels can frag.



Consistantly? That's the question for me. I have no doubt even a 10" barreled AR can fragment a 5.56 round, especially one of the heavier "new age" designed bullets like the 75 gr Hornady TAP (BTHP) or 77 gr Black Hills Sierra MatchKing (BTHP) bullets, but with XM193's? No. Not consistantly like I said.
Link Posted: 10/9/2005 7:44:23 PM EDT
[Last Edit: 10/9/2005 7:49:25 PM EDT by clange]

Originally Posted By Atreides:

Originally Posted By Combat_Jack:
How short of a short barreled rifle are we talking about?



Like the Krinks 8.5" or 10" barrels Jack.

As for snakes choice....SCREW THE NEIGHBORS!!!! LOL!


Again, you didnt specify. Short Barrelled Rifle is anything under 16, but 11.5 is probably the common 'short' length, and the oracle says it will fragment at close distance. Jack claims 10s can, i have no idea. If you get down around 8.5 (or wherever 5.56 will never fragment), no, i dont suppose 5.56 would be better than 7.62 in any category other than overpenetration and recoil.
Link Posted: 10/9/2005 7:47:31 PM EDT
Personally I don't really care if it frags. I'll shoot him till he falls down.

I would pick a 10.5" Noveske, 11.5" Colt or 12.5" Noveske if the NFA were not an issue.
Link Posted: 10/9/2005 8:06:00 PM EDT
[Last Edit: 10/9/2005 8:14:35 PM EDT by Atreides]

Originally Posted By clange:

Originally Posted By Atreides:

Originally Posted By Combat_Jack:
How short of a short barreled rifle are we talking about?



Like the Krinks 8.5" or 10" barrels Jack.

As for snakes choice....SCREW THE NEIGHBORS!!!! LOL!


Again, you didnt specify. Short Barrelled Rifle is anything under 16, but 11.5 is probably the common 'short' length, and the oracle says it will fragment at close distance. Jack claims 10s can, i have no idea. If you get down around 8.5 (or wherever 5.56 will never fragment), no, i dont suppose 5.56 would be better than 7.62 in any category other than overpenetration and recoil.



Well sorry about that clange, but I was talking about the Krinkov, and I am unaware of any Krink over 10" long. Sorry for the mixup.

If you go back and read my original post you'll see that I share your assessment on bullet performance Jack.



A bullet is a bullet, and any bullet through a major organ will eventually stop an enemy.


I still like the Krink as a choice for CQB stuff. NFA aside of course. I like the fact that it uses more powerful rounds than a traditional Subgun, yet boasts a comparable size. Then again, a good old fashioned 12" 870 with 00 buck would work good too, 'cept the Krink has less recoil & muzzle flash. Not to mention report, 12GA shotguns are no fun indoors.


On a side note: You guys brought up the recoil of the 7.62 X 39 round a couple of times, is it considered as a high recoil round? I've never had a problem with it. I think of high recoil as .308 and the likes. Somehow the 7.62 never struck me as a high recoil round...
Link Posted: 10/9/2005 8:23:25 PM EDT
[Last Edit: 10/9/2005 8:24:32 PM EDT by EternalVigilance]
Full fragmentation for M193 requires 2700 fps.  2500-2700 fps still provides SUBSTANTIAL fragmentation.


So yes, M193 does fragment out of short barrelled ARs.  It just doesn't have as much fragmentation range.  If I remember correctly you are looking at about 150 yards out of a 16 inch barrel and 200 out of a 20 inch barrel.  

I would be much more concerne about CQB range fragmentation anyway.  If they are that close I want them out of the fight NOW.  If they are 200 yards away I don't mind as much having to shoot them twice.  (especially since 5.56 is a pretty inherently accurate round )


Basically, 5.56 and 7.62 are both excellent rounds.  7.62 better penetration of cover/armor, 5.56 better against soft targets at close to intermediate range and faster recovery/more controllable.


That's my 2 cents.


Basically if I have four guys about to kick down my door I'd rather have 7.62 so that I can start shooting their single file through the wall.  

They both have their applications, I think 5.56 is better for all around SHTF, but the difference is negligable.    
Link Posted: 10/9/2005 8:50:41 PM EDT
Link Posted: 10/9/2005 8:56:21 PM EDT
[Last Edit: 10/9/2005 8:59:45 PM EDT by Mattl]

Originally Posted By FortyFiveAutomatic:
IIRC the 7.62x39 round is inherently a very accurate round.  More so than the 5.56 if i'm not mistaken.



Your mistaken.  300meters tops out of 16' barrell 20+' RPK barrell 450meters tops unless fired at area target.  AN yes I am an AK lover, not an AR fan.  With a 10' barrel the 7.62X39 breaks .357Mag 'ish in speed.  That said in CQB I would still want the AK.  Know a few combat vets and they all said wounds are far worse with AK and the target is incapacitated faster.  I will take their word for it.


Link Posted: 10/9/2005 9:00:52 PM EDT

Originally Posted By Combat_Jack:
BTW, the 7.62x39mm in ballistic gelatin essentially replicates the performance of .38 Special, a round not known for its superior terminal effectiveness. The .38 enters, yaws and leaves base first. Marshall and Sanow rate that caliber at 50%. So even they do't like it.

However, there is no denying that a LOT of people have been killed with that caliber.

Also, energy transfer is BS. All that matters as a wounding mechanism is the amount and type of destroyed and damaged tissue, the amount of blood loss, etc.



Too bad Combat Jack is too young to have gone to SEA with me. I'd have loved to have given him a .38 and told him " Don't worry, Those Commie guns are no more effective than a .38. Every Jello test proves it!"
Link Posted: 10/9/2005 9:05:07 PM EDT
I don't care how effective a rifle cartridge is. If the person behind the rifle can't hit a damn thing.
The rifle and cartridge is useless. I do understand the effectiveness and characteristics of all 3 calibers but to say one is ineffective is just dumb.
Link Posted: 10/9/2005 9:08:51 PM EDT

Originally Posted By POLYTHENEPAM:

Originally Posted By Combat_Jack:
BTW, the 7.62x39mm in ballistic gelatin essentially replicates the performance of .38 Special, a round not known for its superior terminal effectiveness. The .38 enters, yaws and leaves base first. Marshall and Sanow rate that caliber at 50%. So even they do't like it.

However, there is no denying that a LOT of people have been killed with that caliber.

Also, energy transfer is BS. All that matters as a wounding mechanism is the amount and type of destroyed and damaged tissue, the amount of blood loss, etc.



Too bad Combat Jack is too young to have gone to SEA with me. I'd have loved to have given him a .38 and told him " Don't worry, Those Commie guns are no more effective than a .38. Every Jello test proves it!"



I think he is about 19.  It just shows you not to take everything as gosepel that is said here, that said their is abundant amounts of useful info to be had.
Link Posted: 10/9/2005 9:28:37 PM EDT

Originally Posted By POLYTHENEPAM:

Originally Posted By Combat_Jack:
BTW, the 7.62x39mm in ballistic gelatin essentially replicates the performance of .38 Special, a round not known for its superior terminal effectiveness. The .38 enters, yaws and leaves base first. Marshall and Sanow rate that caliber at 50%. So even they do't like it.

However, there is no denying that a LOT of people have been killed with that caliber.

Also, energy transfer is BS. All that matters as a wounding mechanism is the amount and type of destroyed and damaged tissue, the amount of blood loss, etc.



Too bad Combat Jack is too young to have gone to SEA with me. I'd have loved to have given him a .38 and told him " Don't worry, Those Commie guns are no more effective than a .38. Every Jello test proves it!"



Not saying that it is not an effective round, just that there are more effective rounds.  I don't want to get shot with anything, rifle rounds in particular.

As I said above, a poerful round and fragmentation is good, but a few solid hits is better.

As for the recoil of the M43 round, when used in a Krinkov it is completely uncontrollable.
Link Posted: 10/10/2005 12:14:43 AM EDT
[Last Edit: 10/10/2005 12:28:56 AM EDT by Atreides]

Originally Posted By No1Here:
I don't care how effective a rifle cartridge is. If the person behind the rifle can't hit a damn thing.
The rifle and cartridge is useless. I do understand the effectiveness and characteristics of all 3 calibers but to say one is ineffective is just dumb.



Good point, and very true. I don't think anyone here was implying that any of the rounds were ineffective. As long as it makes a hole, it will work. It's just that some bullets do work better than others for different jobs, that's all.

I'm glad you brought up shooter ability. That's why I prefer a carbine over a handgun for Home Protection. Don't get me wrong, I'll use whatever is available but given a choice I like the added control of a carbine. And then there's the factor of untrained family members. MAybe "untrained" is a bad description but you know what I mean. A rifle is alot easier to handle than a handgun, and more likely to hit whatever it's pointed at. (If you get my meaning).


Also, energy transfer is BS. All that matters as a wounding mechanism is the amount and type of destroyed and damaged tissue, the amount of blood loss, etc.


I don't agree. While blood loss will eventually result in neutralizing an enemy, Henorragic Shock takes time to set in. While this time can be measured in seconds, it still leaves the enemy with the ability to keep shooting at you for those few seconds, bettering his chance of getting you.

Energy trasfer and the shock it causes is what neutralizes quickly. Also known as "Crush Force" the force of the bullet being transferred to the targets body explodes internal organs and distrupts cardiac fuction. It's the transfer of energy that causes secondary wound damage like a temprary cavity being formed within the wound channel, not the bullet itself.
Link Posted: 10/10/2005 12:20:20 AM EDT

Originally Posted By 762bodydropper:
Thank you, I now have a headache.



Me too. Many fallacies .
Link Posted: 10/10/2005 12:43:09 AM EDT

Originally Posted By chewbacca:

Originally Posted By 762bodydropper:
Thank you, I now have a headache.



Me too. Many fallacies .



Yup. WOW. Just WOW.
Link Posted: 10/10/2005 12:56:06 AM EDT

Originally Posted By POLYTHENEPAM:

Originally Posted By Combat_Jack:
BTW, the 7.62x39mm in ballistic gelatin essentially replicates the performance of .38 Special, a round not known for its superior terminal effectiveness. The .38 enters, yaws and leaves base first. Marshall and Sanow rate that caliber at 50%. So even they do't like it.

However, there is no denying that a LOT of people have been killed with that caliber.

Also, energy transfer is BS. All that matters as a wounding mechanism is the amount and type of destroyed and damaged tissue, the amount of blood loss, etc.



Too bad Combat Jack is too young to have gone to SEA with me. I'd have loved to have given him a .38 and told him " Don't worry, Those Commie guns are no more effective than a .38. Every Jello test proves it!"



Not doubting the effectiveness of the caliber. I just don't drink the 7.62 Kool-Aid. Just giving the facts on the tests that were conducted.
Link Posted: 10/10/2005 12:58:53 AM EDT

Originally Posted By Mattl:

I think he is about 19.  It just shows you not to take everything as gosepel that is said here, that said their is abundant amounts of useful info to be had.



And this is relevant how? How long have you been reading everything you found on terminal ballistics, and more importantly, talking to people who have shot people. If you have anything to add to the conversation, feel free to do so. Until that time, please avoid posting.
Link Posted: 10/10/2005 1:14:40 AM EDT

Originally Posted By 53vortec:

Originally Posted By chewbacca:

Originally Posted By 762bodydropper:
Thank you, I now have a headache.



Me too. Many fallacies .



Yup. WOW. Just WOW.



Yeah I know, WOW. Just WOW.  
Link Posted: 10/10/2005 1:24:01 AM EDT
Which are fallacies?
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