.30 cal FMJ rounds, what makes them better then 5.56 FMJ?

[X-Rap]

In a belt fed machine gun mounted or not the caliber choice is obvious, as an individual weapon the choice should be the same.
You see a mix of M2, 240, 249, m4/16 derivatives for a reason. I doubt the modern combat troop yearns for the nostalgia of packing an M1 with its 8 shot clips into battle today anymore than the F15 pilot wishes for a P51.
In any war the ones left in the ground are taken down by what is flying through the air, if the 22 caliber bullets of today were the primary small arms issue of WWII I think the numbers would be very much the same.
In answer to the OP, you are choosing to compare the worst choices for personal defense that you could and depending upon your true intended purpose I'd suggest you get your hands on some actual rifles and compare how they handle if you really are looking for a CQ PD rifle.

 

[HammsBeer]

If the .223/5.56 bullets coated with their pixie dust and unicorn feces are "all that", why are .30 caliber weapons and cartridges still in use in our military?

Proper tool for the job is all. You don't build a cabinet with a sledgehammer, and you don't drive railroad spikes with a carpentry hammer.

Weight. Studies have shown that volume of fire can be a deciding factor in an engagement. More lead downrange equals more hits. So when soldiers are limited in how much they can tote around, it's logical to carry more rounds of a lighter but still effective cartridge. Plus a smaller cartridge is easier to use in rapid shooting and confined spaces such as house clearing.

The downside is the effective range of small cartridges. Beyond a certain distance the 5.56 just runs out of steam, that's why they have designated marksmen with 30 cal or bigger rifles for those longer targets.

 

[X-Rap]

But General Patton said.....

 

[tark]

And General Patton was right.

 

[The Alaskan]

No, .30 isn't all that. 8mm will trump it in every category. So much for faith. Your belief in the cartridge isn't all that.

Yup, and that pretty much definitively supports what people have been saying all along: bigger is, for the most, better.

There are limits to how far that will go, of course. By that logic, every soldier should be toting around a 375 H&H or some other silliness. (Shoulder fired howitzer anyone?)

I would think that a hit to the chest with a 5.56 would greatly limit your chances of survival as well.

Yeah I sure as heck don't want to get shot with one, and I don't think I, or I didn't intend, to assert that a 223 won't kill. There's a lot of dead soldiers to refute that argument as well. (Not as many as the 30 cal.) But, in my mind, this entire discussion is not that the 223 is ineffective, but that 30 cal is MORE effective, especially at distance and especially though cover.

My thoughts are that Jenrick (who's probably still wet behind the ears and from a urban or city area) needs to get out of the books and get onto a range, shoot some gel and see the difference. Then he will know why the .30 is better than the .223.

I wasn't going to say it, but I'm glad someone did. Young people always have some "latest and greatest" wonder toy. Then again, I'm sure that when the Army first switched to 30-06, there were folks like me who asked "What's wrong with my Trapdoor Springfield?"

All in all, I have to agree with 35Whelen; this is getting rather circular.

 

[The Alaskan]

Before I go, I would like to take just a moment to say that anything I have written comes from knowledge learned from the experience of those who came before me. (he World War II and Korea generation.) I don't have any battlefield experience. I believe that to be a blessing from the Lord, and I'm very thankful for that fact. (Just seems like every time there was a deployment, something happened at the last minute and we ended up not going.)

For C-Grunt and others like him, I'm sorry you've had to have those experiences.

 

[Jenrick]

I've gotten a few decent answers out of this thread, but to be honest the vast majority has been simply: "because it worked in WW2!"

To avoid this sliding off the high road I'll PM those whose responses I'd like to follow-up on and if anyone would like to follow up on anything in this thread feel free to shoot me a PM.

Mods can you do me a favor and close this one down.

-Jenrick

 

[C-grunt]

This thread has just about reached the point of irrational ramblings, but just a final thought before I make good use of the "Unsubscribe" feature...

If the .223/5.56 bullets coated with their pixie dust and unicorn feces are "all that", why are .30 caliber weapons and cartridges still in use in our military?

Signing off....

35W

Are you not reading my replies? I've said multiple times that 7.62 outperforms 5.56 in terminal ballistics.

But you can blindly believe what you want. There are a lot of us who do this stuff for a living and have been able to have informed opinions from out experiences. Guys like Vern might have different opinions than mine but again their opinions are based on experience. They don't write ridiculous things like quoted above and understand mixed arms warfare.

 

[The Alaskan]

I've gotten a few decent answers out of this thread, but to be honest the vast majority has been simply: "because it worked in WW2!"

To avoid this sliding off the high road I'll PM those whose responses I'd like to follow-up on and if anyone would like to follow up on anything in this thread feel free to shoot me a PM.

Mods can you do me a favor and close this one down.

-Jenrick

I'm sorry you didn't get the answer you were looking for, or in the format you were looking for. You know, I think we've just talked (typed) past each other...all of us. I think most of the 30 cal adherents are older folks and, to a point, doers rather than thinkers. You wanted an answer is Scientific Notation with research and formulas to back it up, and we're not that crowd. I think I and some others gave you the best answer we could, but we're not going to break out a calculator to prove those answers.

You asked about 30 cal because you were thinking of buying an M1A. But I think you were previously convinced that 30 cal was insufficient or in some way lacking, compared to 223 (if you didn't think that, I doubt you would have even asked), so you should probably stick with what you know...and we'll do the same.

 

[strambo]

Level III AR500 armor is 1/4" so relating it to results on a 3/8" AR500 target is meaningless.

OP didn't even mention as use/mission for said firearm so IMO a meaningful discussion isn't even possible without that context. General combat? SHTF? Home defense? Close Quarter Battle?

Depending on the purpose, the advantages of one cartridge vs. another could be useless in a given context. .30 cal can penetrate better and carry more energy at long range...useless in HD/CQB. The 5.56 is has much lower recoil...not a valid consideration for a machine gun like the M240B.

Mission drives gear and ammo choice, there is no 7.62x51 configuration I would choose for HD, I would pick a .300BLK though. There is no 5.56 I'd choose for a sniper rifle or general purpose machine gun.

 

[Malamute]

Hes not asking for opinions on either cartridge, hes asking what is the physical mechanics of the 30 cal military bullets wounding ability. How does it happen. Its a completely academic question, which most have entirely missed the point on.

Nothing really mathematical about it. I'll look for references, but 30 cal 150-ish gr bullets typically start to yaw several inches into ballistics gel or humans, turning sideways then backwards, and sometimes continuing to turn, sometimes ending up simply going backwards once they turn. Thats the basics of 30 cal FMJ wounding mechanics.

This is a wound profile comparison of various rifle bullets in ballsitc gel, posted elsewhere by Dr Gary Roberts.

http://www.ar15.com/ammo/project/Misc_Images/DocGKR/40053-MilitaryRifleWPcopy.jpg

Theres quite a lot of info, a number of wound proifile comparisons if one does a search for "30 cal FMJ wound profile."

https://www.google.com/search?q=30+...Q_AUoAWoVChMI_bTHpOqOyAIVT06ICh09MQEr#imgrc=_

 

[clang]

OP, if you are still reading this, bullets are not ice picks, they are projectiles traveling at supersonic speeds. The physics involved is different then what most people experience in ordinary life. Add the variability of shooting someone in combat (distance, cover, armor, where hit, etc.) And it is difficult to give a simple answer to what appears on the surface to be a simple question.

when faced with the complexity of such a question, most people will relay on what they've seen or what they've read. .30-06/.308 caliber works, it's probably overkill in many cases.

Note I did not say .30 caliber works, there were plenty of complaints from Korean War vets of the .30 carbine, it wouldn't put the enemy down fast enough.

Colonel Townsend Whelen might have summed up this argument when he said "the .30-06 is never a mistake."

The .223 is enough gun for most combat conditions a GI may encounter in the field. Ithas the added benefit of being a lighter weapon and ammo, so he can carry more into battle while being lighter and faster. The decision on what platform to supply combat troops as a standard weapon includes factors like these.

 

[lysanderxiii]

FMJ works and when considering what military ammunition must do under what conditions the use of FMJ bullets makes sense. Military rifles are not match target rifles, they are designed to function under a given set of harsh conditions. FMJ bullets or "ball" ammunition is a small-arms projectile consisting of a soft core (often lead) encased in a shell of harder metal, such as gilding metal, cupronickel, or less commonly a steel alloy. That definition from the Wiki but I am sure you get the idea. The use of full metal jacketing in military ammunition came about because of the need for improved feeding characteristics in small arms using internal mechanical manipulation of the cartridge to chamber rounds as opposed to externally hand-reloading single-shot firearms. The harder gilding was less prone to deformation than softer exposed lead, which improved feeding. It is often thought that military use of FMJ ammunition was the result of The Hague Convention of 1899, Declaration III, prohibiting the use in international warfare of bullets that easily expand or flatten in the body, but this only addresses that projectiles must not be designed to flatten or expand, not that they be jacketed. Jacketed bullets had been in use since at least 1882. Keep in mind that soft or hollow point rifle ammunition is more susceptible to abuse and also feeding problems that plain Jane FMJ.

As to calibers? The US adopted the 1906 Springfield to replace the 1903 Springfield in 1906. The original 03 Springfield cartridge replaced the 30-40 Craig which replaced the Government 45-70 with the 30-40 Craig being the first smokeless powder cartridge. Prior to WWII considerable thought went into replacing the 30-06 Springfield. The 276 Pederson was one possible. Unfortunately WWII came along quickly and it was decided to stay with the 30-06 which we had millions of rounds of and was usable in our infantry rifles as well as light machine guns.

I am not a cartridge buff but we have some members who can likely very well answer your question regarding change. Change was very much sought and I can tell you such decisions are not all that simple as politics more often than not drives the winds of change.

Ron

Krag....

His name was Ole Krag, the other guy was Erik Jørgensen.

.30-40 Krag was not the first smokeless powder cartridge, it came very late in the game.

Balle M (8mm Lebel) was adopted in 1886, and was the first military adopted smokeless cartridge, it used a 230 grain flat nosed fully jacketed projectile (for safe use in the tubular magazine of the Lebel rifle). Balle M was replaced in service by Balle D, which was the first Spitzer bullet placed in service by any military, and also the first boat-tailed spritzer as well.

The US adopted .30-40 Krag in late 1892, by that time most of Europe had made the switch to smokeless propellant....

As to .276 Pedersen, it was recommended for adoption in 1932, before Hitler even became Chancellor of Germany, (in fact, he had just lost the election to Hindenburg), and Japan had just occupied Manchuria, but it would be another five years before they would invade China.

The recommendation for adoption of .276 Pedersen was rejected by the Army Chief of Staff (General Douglas MacArthur), as he felt that as long as Garand's design could function properly with currently stockpiled .30 caliber ammunition (mostly M1906/M1 Ball) a change in ammunition was unwise as this would entail the development of a new light automatic rifle to replace the M1918 BAR in .276, as well as a new medium/heavy machine gun to replace the M1917 and M1919. And, given the budget situation in 1932 (four years into the Great Depression), these projects would be suffer from long delays, not to mention that the production of the new .276 ammunition would be very slow.

Good call, but unfortunate, as 7mm seems to be a better projectile diameter. In addition to the US spending a lot of time and money finding 7 mm to be the optimum caliber, the British spent a lot of time and money finding this out twice, once in 1912-13 as .276 Enfield, and again in 1945-1955 as .280 British, 7mm "Optimum", 7mm High Velocity, 7mm "Compromise", 7mm "Second Optimum". It is interesting to note that 7mm Compromise, is almost exactly the same as 7mm-08...

 

[X-Rap]

Interesting history and as is often the case it shines light on some whys that go beyond what may be our first notions on the matter.
I find it interesting that the US .30 survived more due to stockpiles of ammo and weapons than its superior performance on the battlefield.
Thankfully Gen. MacArthur had enough "Pixie Dust" and "Unicorn Feces" to save the free world since we all know the 7mm is superior to the 30:banghead:

 

[Reloadron]

Krag....

His name was Ole Krag, the other guy was Erik Jørgensen.

.30-40 Krag was not the first smokeless powder cartridge, it came very late in the game.

Balle M (8mm Lebel) was adopted in 1886, and was the first military adopted smokeless cartridge, it used a 230 grain flat nosed fully jacketed projectile (for safe use in the tubular magazine of the Lebel rifle). Balle M was replaced in service by Balle D, which was the first Spitzer bullet placed in service by any military, and also the first boat-tailed spritzer as well.

The US adopted .30-40 Krag in late 1892, by that time most of Europe had made the switch to smokeless propellant....

As to .276 Pedersen, it was recommended for adoption in 1932, before Hitler even became Chancellor of Germany, (in fact, he had just lost the election to Hindenburg), and Japan had just occupied Manchuria, but it would be another five years before they would invade China.

The recommendation for adoption of .276 Pedersen was rejected by the Army Chief of Staff (General Douglas MacArthur), as he felt that as long as Garand's design could function properly with currently stockpiled .30 caliber ammunition (mostly M1906/M1 Ball) a change in ammunition was unwise as this would entail the development of a new light automatic rifle to replace the M1918 BAR in .276, as well as a new medium/heavy machine gun to replace the M1917 and M1919. And, given the budget situation in 1932 (four years into the Great Depression), these projects would be suffer from long delays, not to mention that the production of the new .276 ammunition would be very slow.

Good call, but unfortunate, as 7mm seems to be a better projectile diameter. In addition to the US spending a lot of time and money finding 7 mm to be the optimum caliber, the British spent a lot of time and money finding this out twice, once in 1912-13 as .276 Enfield, and again in 1945-1955 as .280 British, 7mm "Optimum", 7mm High Velocity, 7mm "Compromise", 7mm "Second Optimum". It is interesting to note that 7mm Compromise, is almost exactly the same as 7mm-08...

My bad in that I should have pointed out US Military smokeless cartridge.

On a side note this thread has taken the usual 223 versus 308 route which sort of sucks. Don't see where any of this really matters unless the OP plans to drag the M1A he is considering buying into combat? I asked sometime back what was the intended application for the rifle? Seems simple enough to me.

Ron

 

[Shawn Dodson]

M193 55gr FMJ performs better (albeit slightly) through laminated automotive windshield glass than M855 62gr FMJ. (Personally, I prefer M193 over M855 as a general-purpose "emergency preparedness" cartridge.)

The initial wound track of the M80 147gr FMJ, in a "simple wound" involving soft tissues only, shows very little disruption. In fact, the wound produced in the first six inches of penetration is indistinguishable from the wound produced by a .32 ACP FMJ pistol bullet. It is only when the M80 bullet yaws that it produces substantial disruption, creating a temporary cavity roughly 8x10 inches in size, which no soft tissues in the body can tolerate.



If the bullet strikes the body at a tangent and yaws earlier, is destabilized by striking an object prior to impact with the body, or strikes bone shortly after penetration (a "complex wound") (destabilizing and deforming the bullet), then a greater wounding effect will occur at a shallower penetration depth.

M193/M855 produces a temporary cavity approximately 6x6" in size.





An M80 bullet simply possesses greater mass and momentum than M193/M855, which translates in to greater wounding effect. It is the transfer of the momentum (not energy) from the bullet to soft tissues that produces the temporary cavity.

 

[Bama Drifter]

Throw a pebble at someone. Now throw a brick at them. Nuff said.

^ Yep.

At the risk of sounding unreconstructed: IT KILLS STUFF DEADER! Now let's unpack that pithy, loaded aphorism. If sugar turns to cr@p and it is you or some guy behind hard cover wouldn't you want a .308? Simple question, simple answer. Try to chew through cinderblock w/ 62 to 75gr 5.56 ....and after wasting 10 or a dozen mags worth of effort, load up 20rds of good ole M80 NATO and see the block disintegrate!
https://en.wikipedia.org/wiki/7.62×51mm_NATO

FWIW, I'm a 32 year old who likes the old fashioned stuff... no need to be "tacticool".

 

[Vern Humphrey]

Try to chew through cinderblock w/ 62 to 75gr 5.56 ....and after wasting 10 or a dozen mags worth of effort, load up 20rds of good ole M80 NATO and see the block disintegrate!

At the Infantry School at Fort Benning, they used to have display boxes on the walls for all sorts of interesting stuff. While I was there, the Army developed a DPICM (dual purpose improved conventional munitions) round for the M79/M203 40mm grenade launcher. This was basically a shaped charged with a fragmentation sleeve wrapped around it.

This round was on display in one of those boxes, with photographs of a concrete block wall that had been shot with the DPICM round and the caption, "Impressed?"

Someone wrote on the glass front with a grease pencil, "Hell no! I've seen what an M14 will do to concrete blocks."

 

[C-grunt]

Bama Drifter... you should go shoot some of these things before you post ridiculous things.

 

[Malamute]

Don't see where any of this really matters unless the OP plans to drag the M1A he is considering buying into combat? I asked sometime back what was the intended application for the rifle? Seems simple enough to me.

His intended use of the rifle has zero to do with the question, other then being the genesis of it.

Originally Posted by Jackal
Throw a pebble at someone. Now throw a brick at them. Nuff said.

^ Yep.

Nope.

Besides being entirely off topic, and the first part is so far off into ridiculous land as to be very humorous.

Can anyone reiterate the question? Most of the posts are off topic (not all, Shawn Dodson #66 was completely on topic and answered the question). Not that off topic is all bad, but I think most think they are on topic.

If in doubt of the basic question, see first paragraph of post 61.

 

[AStone]

Can anyone reiterate the question?

Copy.

So what is it that makes the 7.62 NATO and the venerable .30-06 such a superior combat cartridge in terms of lethality to the 5.56?
Beyond the need to reach out and touch someone (often overstated) by what mechanism is the .30 FMJ bullet made superior t0 the 5.56?

 

[Malamute]

I think I did a pretty good job of answering the OPs question with this answer.

Indeed.



Well done AStone!

So what is it that makes the 7.62 NATO and the venerable .30-06 such a superior combat cartridge in terms of lethality to the 5.56?
Beyond the need to reach out and touch someone (often overstated) by what mechanism is the .30 FMJ bullet made superior t0 the 5.56?

The question was the mechanics of how the bullet perfoms. What it does to cause wounds.

However, some of the off topic discussion was truly interesting. Some quite humorous.

 

[DaisyCutter]

How can anyone honestly not understand how one projectile with 3X the mass and 2X the energy of the other, is more effective.

I got two tube socks loaded with quarters, but one weighs 3X more and I'm going to have you hit me with that heavier one twice as hard, so I can see which of the two hurts more.

Well, duh.

The real question is how anyone can claim the projectile weighing a third as much, with half the energy, can be as effective as the bigger & harder hitting one. This is where the magic voodoo yawing/fragmenting/elastic/radioactive theories come into play.

Granted, the package of the lighter recoiling rifle with the higher volume of fire may be better suited for combat deployment, that assertion falls outside the scope of which individual projectile is more effective.

Comparing sniper cartridge choices is a better "bullet for bullet" effectiveness gauge.

Bullet for bullet, the 30-06/308 dominates the 223. Snipers are going bigger now... 300 Win Mag, 338...

The 338 is heavier, bigger diameter, and carries more energy than the 30-06, and in terms of effectiveness, it dominates the 30-06.

If someone can't understand this, then they need to move into a rubber bubble before they get hurt. It's a dangerous world when you think stepping in front of an oncoming car will hurt no more than stepping in front a kid on a bicycle.

 

[AStone]

I got two tube socks loaded with quarters

Wait .. this could be a 2-bit whore!

Just kidding ..

 

[C-grunt]

How can anyone honestly not understand how one projectile with 3X the mass and 2X the energy of the other, is more effective.

I got two tube socks loaded with quarters, but one weighs 3X more and I'm going to have you hit me with that heavier one twice as hard, so I can see which of the two hurts more.

Well, duh.

The real question is how anyone can claim the projectile weighing a third as much, with half the energy, can be as effective as the bigger & harder hitting one. This is where the magic voodoo yawing/fragmenting/elastic/radioactive theories come into play.

Granted, the package of the lighter recoiling rifle with the higher volume of fire may be better suited for combat deployment, that assertion falls outside the scope of which individual projectile is more effective.

Comparing sniper cartridge choices is a better "bullet for bullet" effectiveness gauge.

Bullet for bullet, the 30-06/308 dominates the 223. Snipers are going bigger now... 300 Win Mag, 338...

The 338 is heavier, bigger diameter, and carries more energy than the 30-06, and in terms of effectiveness, it dominates the 30-06.

If someone can't understand this, then they need to move into a rubber bubble before they get hurt. It's a dangerous world when you think stepping in front of an oncoming car will hurt no more than stepping in front a kid on a bicycle.

When a 5.56 yaws and fragments it can (as in capable of) indeed be "as effective" as a 7.62 NATO. When both rounds work as advertised both will remove large portions of your head or turn someones chest cavity into mush. If you really doubt 5.56 effectiveness Google pictures of 5.56 wounds. Warning some of it is very gruesome.

However, no one I have seen has said that the 5.56 out performs the 7.62 NATO in the terminal ballistics category. What we have said is the 5.56 is effective at doing its job while giving the shooter more ammo for the weight, more ammo in the gun, less recoil, and a lighter rifle.

Also, these analogies are not very good. Bricks and socks filled with change and cars all injure by blunt force trauma. Different wounding mechanism than rifle rounds. Since leaving the Army I have become a cop for a major metro department. Ive seen a bunch of injuries due to thrown items, clubing items, and vehicle collisions.