5.56

[Leagle]

just wondering, but, are u allowed 2 use a 5.56 bullet in ur weapons?

and

is it true that a 5.56 bullet, upon entering the body, turns on its side and rips the muscle etc?

 

[nwilliams]

I have a .223/5.56 AR-15 and many boxes of ammo that say 5.56 on the front, so I guess the answer to the first part of your question is yes.

As for the bullet tumbling when it enters the body, I've heard that it does but I'm not ballistics expert, others should be able to give a precise answer on that.

 

[The Deer Hunter]

I Beleive the 7.62x39 round tends to turn once it enters the body, which is also known as keyholing, more often than the 5.56.

 

[Mr White]

Yes. The 5.56x45 NATO/.223 Remington is legal here and is in fact, a VERY popular cartridge for varmits, plinking and competition shooting.

The 5.56 bullet will tumble when it hits flesh and will fragment if its moving at or faster than 2800 fps.

Check out this site to learn more than you ever wanted to know about the 5.56/.223 round.

 

[JesseL]

If you're asking if the 5.56x45mm NATO round is legal in the USA, the answer is yes.

As for the tumbling bullet, most full metal jacket bullets with a spitzer shape will tumble when they encounter flesh, assuming they have sufficient velocity and correct degree of spin stabilization. This is a pretty straightforward result of the bullets center of gravity being biased to the rear - they want to travel rear first but the rifling induced spin stabilization prevent this until something upsets their stability. I think this effect was first utilized in the 1890's by the 7mm Mauser round.

Keyholing is the name for when a bullet isn't adequately stabilized and begins tumbling in the air. It's so named because of the slot shaped holes the bullets leave in targets when they penetrate sideways.

 

[glockman19]

Yes and Yes

 

[Leagle]

few more questios =\

what does NATO mean and fps and what does the x45 mean in 5.56x45

 

[R.W.Dale]

North
Atlantic
Treaty
Organization


the x45 denotes the case length expressed in milimeters

 

[JesseL]

NATO is the North Atlantic Treaty Organization.

FPS is Feet Per Second. This is typically how the velocity of bullets are expressed in the US.

The 45 in 5.56x45mm NATO is the length of the cartridge case.

 

[Warbow]

And just to clarify, the tumbling of spitzer bullets in fluid mediums denser than air was a side effect and not a primary design concern. Spitzer bullets were designed because they greatly increased the ballistic coefficient (due to better aerodynamics) compared to the conical bullets in use in the late 1800s. This translated to better trajectories, velocity and retained energy.

 

[Leagle]

alright sweet thanks

 

[kcmarine]

NATO stands for North Atlantic Treaty Organization. It is the allied organization that the U.S. and several other countries belong to. Its original purpose was to defend Western Europe from a Soviet invasion. Now, it is used to dispatch member nations' troops to world hot spots.

The NATO designation in 5.56x45mm NATO comes from the round being a standard issue round for the organization's rifles.


FPS stands for Feet Per Second. How many feet the bullet travels in a second when fired.

The x45 in 5.56x45mm NATO stands for the cartridge length. It is 45 millimeters long.

 

[Glockfan.45]

Modern M885 ammo (5.56x45mm) does not tumble. Its stoping power comes from fragmentation. The older M193 was a tumbling round AFAIK.

 

[Warbow]

Modern M885 ammo (5.56x45mm) does not tumble. Its stoping power comes from fragmentation. The older M193 was a tumbling round AFAIK.

Both rounds are capable of fragmentation, and they both tumble (as all bullets with a center of gravity towards the base will).

The fragmentation comes from the bullet trying to right itself around its center of gravity. If the velocity is high enough, as the bullet turns and begins to travel sideways through flesh the force is sometimes enough to cause it to come apart.

Of course, fragmentation won't occur every time as many factors come into play. One of the big ones being if the bullet starts to flip around too late and exits before it becomes sideways.

 

[possum]

check out www.ammo-oracle.com

 

[benEzra]

FWIW, 5.56x45mm is the least powerful of all common centerfire rifle calibers. It's not the Hammer of Thor that the media would have you believe. A .30-06 deer rifle is more than twice as powerful, in terms of kinetic energy.

5.56x45/.223 was developed from a cartridge (.222 Remington) designed for hunting groundhogs and prairie dogs, and other small animals. Its virtue was light weight and low recoil, not lethality.

 

[1911_Mitch]

Wounding effects are sometimes thought of to be more effective in battle than killing effects (of course its the desk jockys not in battle that think this)

(It takes at least one person (sometimes two) to help a wounded person. One killed person is one killed person.)

 

[trstafford]

originally the M-16 had a slower twist so the bullet was unstable and would tumble easily upon contact. Then some genius general realized that in sub-zero weather it did not meet the minimum accuracy requirement. Thus they started using a faster twist which increased accuracy but reduced the tumbling effect thus wounding effect. since 5.56 Full Metal Jacketed bullets don't expand like soft pointed .223 bullets the tumblling caused by slow twist rate was the reason original M-16s were devastating and mow they are looking for more powerful rounds. There is a minor difference between the 5.56 and .223 so that chambers for .223 might not chamber military ammo as well.

 

[pdowg881]

So would it be a step back to go back to the old twist rate and bullet?

 

[1911 guy]

Yes, it would be a step back.

The reat value lies in the bullet. A slightly heavier bullet will retain velocity longer, giving greater effective range. The faster twist rate stabilizes the bullet better and allows for accurate shooting farther than the M193 and a 1:12 twist.

 

[TheDisturbed1]

My grampa was giving my some education on his days in the Army back in the '60s, and he said that one thing about the M14 (which is a different round, i know) was that this "keyhole" effect would prove very effective in combat...

I havent heard any stories to back that up, but it makes sense to have a .30 bullet making a much bigger hole out than in being effective.

Now... ive noticed debates about the difference between 5.56x45 and .223REM, and i hear that some rifles wont load the NATO round correctly into a .223 chamber (or maybe is it the other way around? ).

Buuut... if you think 5.56 is cool, just wait until you get into .50BMG
so cool that the concussion wave can make you wet, then DRY your pants lol
(slight exaggeration, but mighty inspiration)

 

[Bartholomew Roberts]

Wounding effects are sometimes thought of to be more effective in battle than killing effects

Army drill sergeants have certainly used this line to convince recruits that their new weapon is effective and build confidence; but there is no evidence that this was ever a consideration in the selection of the caliber. Most of the evidence indicates that the M16 was basically an intermediate step towards the SALVO project that the Army really wanted and that nobody expected it would serve 40 years.

The primary purpose in the smaller round that is supported by documentation is a larger ammo load out and increased likelihood of hits.

originally the M-16 had a slower twist so the bullet was unstable and would tumble easily upon contact. Then some genius general realized that in sub-zero weather it did not meet the minimum accuracy requirement. Thus they started using a faster twist which increased accuracy but reduced the tumbling effect thus wounding effect.

Gun store myth. As others have already said, all spitzer rounds tumble when they hit a fluid medium because of their center of gravity, even .308 and .30-06. The difference in terminal ballistics depends on when they tumble and how well the bullet survives the event.

The change of the barrel twist from 1/14 to 1/12 has ZERO to do with the effectiveness of the round in flesh. In order to change the twist enough so that it would be spin stabilized in a fluid medium like the human body, you would need rifling that looks like a machine screw. Check out the ammo oracle link listed above.

 

[Frog48]

are u allowed 2 use a 5.56 bullet in ur weapons?

You're "allowed" to do whatever you want... Who's gonna stop you?

However its not a good idea to use 5.56 NATO cartridges in .223 Rem chambers, however its prefectly fine to do the opposite.

 

[SDC]

....is it true that a 5.56 bullet, upon entering the body, turns on its side and rips the muscle etc?

Yes, but this happens with ALL bullets to some extent; the .303 Mk VII (the standard Commonwealth rifle ammunition from World War One through to the 1970s) was designed to do exactly the same thing, by using a lightweight nose core in front of a lead base core. When these rounds hit a target, the bullets twist sideways, sometimes breaking apart. But, since the .303 has a lot more energy, it does a lot MORE damage when doing so.

 

[pdowg881]

I believe 5.56 shouldn't be loaded into a .223 because of the higher pressures correct? But loading .223 in a 5.56 would be ok.