.223 tumble?
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oldbillthundercheif
Moderator
That's one of the all-time-classic 5.56 myths. No, it flies like any other stabilized projectile but sometimes will tumble upon hitting something squishy.
ANY bullet, upon hitting a target, can tumble. Smaller bullets are more liable to do this than heavier ones. The 5.56 became famous (or infamous) for bullets tumbling when stories came back from VietNam about people shot in the leg and the bullet exiting through their arm, or other such fairy tales. While the 5.56 bullet is not designed to tumble, the bullet is so small and easily upset that it can easily tumble upon hitting something.
Sounds like you have half the information you need. Perhaps someone has been pulling your leg a little?
Any insufficiently stabilized bullet, .223 or otherwise, will tumble through the air, "keyholing" as it hits the target - making a keyhole shape on the target as the bullet impacts more or less sideways.
.223 example: shooting a 77 grain bullet out of a barrel with a 1:12" twist.
A properly stabilized bullet (.223 or otherwise) will, of course, travel normally through the air.
Stabilization has to do with twist rate, velocity, bullet length, and to some extent bullet weight. I'm sure someone will shortly come along and provide a more scientific explanation.
Any insufficiently stabilized bullet, .223 or otherwise, will tumble through the air, "keyholing" as it hits the target - making a keyhole shape on the target as the bullet impacts more or less sideways.
.223 example: shooting a 77 grain bullet out of a barrel with a 1:12" twist.
A properly stabilized bullet (.223 or otherwise) will, of course, travel normally through the air.
Stabilization has to do with twist rate, velocity, bullet length, and to some extent bullet weight. I'm sure someone will shortly come along and provide a more scientific explanation.
Mike Irwin
Staff
Yep, it tumbles while flying through the air.
Which, of course, is why, when combined with its incredibly high velocity, it doesn't even need to hit the intended target, just come fairly close to effect a lethal wound.
And if it DOES manage to hit the target?
The energy release is akin to a 1 megaton atomic explosion.
Which, of course, is why, when combined with its incredibly high velocity, it doesn't even need to hit the intended target, just come fairly close to effect a lethal wound.
And if it DOES manage to hit the target?
The energy release is akin to a 1 megaton atomic explosion.
hdawson228
New member
The round travels through the air "on the verge of instability" then will tumble when it penetrates the bg.
RockyMtnTactical
New member
The .223 if going fast enough will tumble upon impact of soft tissue. Some other bullets will do this if they are traveling fast enough as well.
RedneckFur
New member
The only bullet i can think of thats designed to tumble is older .303 british surpluss FMJ. It's weighted heavier at the base to cause it to yaw sideways on impact, but its stable in flight.
MD_Willington
New member
Some of the really old .303 has a wooden tip under the jacket...
The old M16s of the Viet Nam era had twist rates of 1:14" and it would not stabilize the M193 55 gr FMJ bullet in low temps. Because all bullets with the shape of a spitzer have a tendency to tumble and the lack of sufficient twist, the M193 bullets would indeed tumble and sometimes wouldn't get to the 100 meter target. Here's a copy of a teminal ballistics commentary:
TERMINAL BALLISTICS
There are two different aspects to this; the effect of projectile strike against soft targets (animals or people) and the effect against armour.
First, against soft targets (the squeamish have permission to duck this section!). A military (i.e. fully jacketed, pointed, non-expanding) rifle bullet will be destabilised when hitting a soft target and will tumble. This is because its shape means that the centre of gravity of the bullet is towards the rear so it naturally prefers to fly base-first. Spinning the bullet by means of the rifling keeps the bullet flying point-first through the air, but flesh is about 400 times denser than air so spinning is no longer enough; the bullet destabilises and turns over to travel base-first, a process known as tumbling. In so doing it obviously inflicts a far more serious wound than if it carried on flying straight through the body. Incidentally, bullets designed for penetrating heavy game animals like elephant - which need to penetrate very deeply and must therefore not tumble - have long, parallel sides and blunt round noses, just like early military rifle bullets.
Not all bullets tumble at the same rate. Other things being equal, small bullets will tumble more quickly than large ones, but the design of the bullet is also important; some visibly identical bullets will tumble at different speeds, generally depending on the internal construction. For example, the Yugoslavian bullet for the 7.62x39 has a lead core and has been found in tests to tumble much more quickly than the Russian steel-cored bullet in the same cartridge. Readiness to tumble may also be affected by how well-stabilised the bullet has been by the rifling. A well-stabilised bullet may pass straight through the target without having time to tumble. The original US Army .223 (5.56mm) 55 grain (3.56g) M193 bullet was notorious for rapid tumbling, but the current NATO 62 grain (4.02g) SS109/M855 bullet is fired from rifles with a much steeper rifling twist (1 turn in 7 inches - 18cm - instead of 1 in 12 - 30cm) and is more stable, to the benefit of long-range accuracy and penetration but at the cost of a slightly slower rate of tumble on impact. Various tricks have been used to increase the probability of a bullet tumbling; the British .303 Mk VII bullet had a lightweight tip filler with the weight concentrated towards the rear of the bullet, and the current Russian 5.45mm rifle bullet has a hollow tip.
If a bullet has a relatively weak jacket, the stresses of tumbling may cause it to break apart while it is travelling sideways through flesh - a process known as fragmentation - which further increases the wounding effect. Most 5.56x45 military bullets fragment, although they have to be travelling at high velocity to do so. This limits their maximum effectiveness to fairly short range, particularly from short-barrelled carbines which have a lower muzzle velocity. Most 7.62x51 NATO bullets do not fragment, although the German one does - by accident rather than design. Fragmentation is not an official requirement for any military bullets; if it were, there might be some legal challenge over the international prohibition on bullets designed to cause unnecessary suffering. The noses of hunting rifle bullets (and many commercial handgun bullets) are designed to expand on impact, which greatly increases the size of the wound channel. Such bullets are illegal for military use.
TERMINAL BALLISTICS
There are two different aspects to this; the effect of projectile strike against soft targets (animals or people) and the effect against armour.
First, against soft targets (the squeamish have permission to duck this section!). A military (i.e. fully jacketed, pointed, non-expanding) rifle bullet will be destabilised when hitting a soft target and will tumble. This is because its shape means that the centre of gravity of the bullet is towards the rear so it naturally prefers to fly base-first. Spinning the bullet by means of the rifling keeps the bullet flying point-first through the air, but flesh is about 400 times denser than air so spinning is no longer enough; the bullet destabilises and turns over to travel base-first, a process known as tumbling. In so doing it obviously inflicts a far more serious wound than if it carried on flying straight through the body. Incidentally, bullets designed for penetrating heavy game animals like elephant - which need to penetrate very deeply and must therefore not tumble - have long, parallel sides and blunt round noses, just like early military rifle bullets.
Not all bullets tumble at the same rate. Other things being equal, small bullets will tumble more quickly than large ones, but the design of the bullet is also important; some visibly identical bullets will tumble at different speeds, generally depending on the internal construction. For example, the Yugoslavian bullet for the 7.62x39 has a lead core and has been found in tests to tumble much more quickly than the Russian steel-cored bullet in the same cartridge. Readiness to tumble may also be affected by how well-stabilised the bullet has been by the rifling. A well-stabilised bullet may pass straight through the target without having time to tumble. The original US Army .223 (5.56mm) 55 grain (3.56g) M193 bullet was notorious for rapid tumbling, but the current NATO 62 grain (4.02g) SS109/M855 bullet is fired from rifles with a much steeper rifling twist (1 turn in 7 inches - 18cm - instead of 1 in 12 - 30cm) and is more stable, to the benefit of long-range accuracy and penetration but at the cost of a slightly slower rate of tumble on impact. Various tricks have been used to increase the probability of a bullet tumbling; the British .303 Mk VII bullet had a lightweight tip filler with the weight concentrated towards the rear of the bullet, and the current Russian 5.45mm rifle bullet has a hollow tip.
If a bullet has a relatively weak jacket, the stresses of tumbling may cause it to break apart while it is travelling sideways through flesh - a process known as fragmentation - which further increases the wounding effect. Most 5.56x45 military bullets fragment, although they have to be travelling at high velocity to do so. This limits their maximum effectiveness to fairly short range, particularly from short-barrelled carbines which have a lower muzzle velocity. Most 7.62x51 NATO bullets do not fragment, although the German one does - by accident rather than design. Fragmentation is not an official requirement for any military bullets; if it were, there might be some legal challenge over the international prohibition on bullets designed to cause unnecessary suffering. The noses of hunting rifle bullets (and many commercial handgun bullets) are designed to expand on impact, which greatly increases the size of the wound channel. Such bullets are illegal for military use.
Mike Irwin
Staff
"The only bullet i can think of thats designed to tumble is older .303 british surpluss FMJ."
Others, as well, including the Italian 7.35 Terni and the current Russian 5.45 bullets.
Both were designed to make the tips as light as possible so that the bullet would become unstable rapidly on hitting a target.
Others, as well, including the Italian 7.35 Terni and the current Russian 5.45 bullets.
Both were designed to make the tips as light as possible so that the bullet would become unstable rapidly on hitting a target.
Art Eatman
Staff in Memoriam
Lotsa yak-yak about the 5.56/.223, but there's a serious absence of magic. It's faster than a .22 rimfire or a .22 Hornet, but nowhere near the speed of a .220 Swift. They're all .22s, though, which oughta tell somebody something about the credibility of yak-yak.
Lotsa folks out there, if I could buy them for what they know and sell them for what they think they know, I'd light my cigars with Bill Gates' money. The Powerball Lottery would be chump change.
So: For any bullet, there is some rate of twist that will stablilize it. Generally, short/shortish/shorter/lighter bullets in any given caliber require a slower twist for stability. Conversely, long/longish/longer/heavier bullets in any given caliber require a faster twist for stability. It's that simple.
Take a slow-twist barrel, DESIGNED for shorter/lighter bullets and load a long, heavy bullet. Say, .223; a 50-grain barrel with 70-grain bullets. Unstable. Might keyhole. No magic involved. But it can happen with 6mm, 7mm,. 30-caliber, etc. etc.
, Art
Lotsa folks out there, if I could buy them for what they know and sell them for what they think they know, I'd light my cigars with Bill Gates' money. The Powerball Lottery would be chump change.
So: For any bullet, there is some rate of twist that will stablilize it. Generally, short/shortish/shorter/lighter bullets in any given caliber require a slower twist for stability. Conversely, long/longish/longer/heavier bullets in any given caliber require a faster twist for stability. It's that simple.
Take a slow-twist barrel, DESIGNED for shorter/lighter bullets and load a long, heavy bullet. Say, .223; a 50-grain barrel with 70-grain bullets. Unstable. Might keyhole. No magic involved. But it can happen with 6mm, 7mm,. 30-caliber, etc. etc.
, ArtMike Irwin
Staff
Geez, Art, aren't you done yak-yak-yakking yet? 
rickomatic
New member
Here is the definitive article on 5.56 ammunition. It includes a section on "tumbling" which as stated above is in fact true when dealing with unstabilized bullets resulting from bullet size in relationship to barrel twist.
http://http://www.ammo-oracle.com/body.htm
http://http://www.ammo-oracle.com/body.htm
The .223 doesn't just tumble on impact with soft targets.
Several years ago I did a comparison between a 55-grain .223 FMJ and a 115-grain 9mm FMJ in my penetration box. Both shot from the same short distance, both from 16-inch barrels.
The .223 tumbled as it passed through several 1-inch pine board squares and came to rest in the last one it impacted, facing back toward me. The 9mm bullet did not tumble, and actually penetrated farther.
When people talk about .223s tumbling, and stabilization, you need to differentiate between both in flight, and on impact.
Denis
Several years ago I did a comparison between a 55-grain .223 FMJ and a 115-grain 9mm FMJ in my penetration box. Both shot from the same short distance, both from 16-inch barrels.
The .223 tumbled as it passed through several 1-inch pine board squares and came to rest in the last one it impacted, facing back toward me. The 9mm bullet did not tumble, and actually penetrated farther.
When people talk about .223s tumbling, and stabilization, you need to differentiate between both in flight, and on impact.
Denis
Tumble on impact
Lots of bullets will, if they hold together, notably spitzer types mostly. The Military made a big deal of telling the troops about the tumbling and how deadly it was, in order to restore the morale of the troops who weren't confidant with the "tiny" new 5.56mm round, being used to the 7.62mm Nato (.308 Win) and the .30-06.
GI bullets from the Nato round and the '06 will tumble also, but they have to go through a lot more flesh (around 18" IIRC) before they end up base first. Usually they are through the body by that time.
Bullets that tumble in the air do not strike the target with accuracy. They can wind up several inches to several feet off from the point of aim. This is not a desirable feature for a military weapon (or a civilian one), and would not be issued/adopted. Likewise a civilian round that tumbled wouldn't sell well either. Whoever says they (are supposed to) tumble in the air doesn't know what they are talking about.
Lots of bullets will, if they hold together, notably spitzer types mostly. The Military made a big deal of telling the troops about the tumbling and how deadly it was, in order to restore the morale of the troops who weren't confidant with the "tiny" new 5.56mm round, being used to the 7.62mm Nato (.308 Win) and the .30-06.
GI bullets from the Nato round and the '06 will tumble also, but they have to go through a lot more flesh (around 18" IIRC) before they end up base first. Usually they are through the body by that time.
Bullets that tumble in the air do not strike the target with accuracy. They can wind up several inches to several feet off from the point of aim. This is not a desirable feature for a military weapon (or a civilian one), and would not be issued/adopted. Likewise a civilian round that tumbled wouldn't sell well either. Whoever says they (are supposed to) tumble in the air doesn't know what they are talking about.
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