difference between .223 and 5.56

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I'm still trying to learn about different types/sizes of ammo. Whats the difference if any between .223 and 5.56. I was under the impression they're the same type but I just wanna make sure. And also is 5.45 larger than 5.56? I think I tend to confuse myself. Thank (don't bash me too much just learning) Also whats a good brand. [smile]
 
5.56 is the military version of the .223. It is loaded to a slightly higher KABAM factor than .223. Most AR's are OK for 5.56, but some of the bolt actions are not. You need to check your particular gun

so 5.56 can't be used with all .223 weapons. I'm asking this because I have some 5.56 and .223 ammo and I'm buying an AR-15 and wanna make sure I get the right one. I ordering it from www.smith-wesson.com
 
so 5.56 can't be used with all .223 weapons. I'm asking this because I have some 5.56 and .223 ammo and I'm buying an AR-15 and wanna make sure I get the right one. I ordering it from www.smith-wesson.com

I don't claim to be an expert on this but the Smith AR ought to be perfectly fine with 5.56. Whatever you buy just double check. Again, most of the ARs are
chambered for 5.56 but some of the other hunting guns are not. You should be able to figure it out online.
Have fun[grin]
 
If you buy an upper chambered for .223 wylde, you can shoot both with no worries.

If its chambered for .223 then it can't use 5.56. Says in the article above that 5.56 is 60,000 CPU and .223 is 50,000 CPU. So this is telling me that a rifle chambered for 5.56 can handle both 5.56/.223 and a rifle chambered for .223 cannot handle 5.56 mm. Am I getting this right??
 
The higher pressure due to the gunpowder loading is not really the issue (but it doesn't help), it is the way the lands are cut in the barrel. A .223 barrel has a shorter region before the rifling starts, so the slightly longer 5.56 bullet sits on the lands without a gap, and when fired immediately has tighter obstruction and therefore higher barrel pressure. In a barrel made for 5.56, there is a bigger area of "sloppiness" before the lands start, so there is a space for the bullet to accelerate without land friction, so the pressure immediately on firing the 5.56 in the right barrel is lower.

You can fire a .223 in the 5.56 anytime, because it is a little shorter bullet in a longer open space. The only drawback is that you loose a little accuracy when doing so, I guess because the bullet wobbles around a little due to the longer gap space.

That is the way I understand it.
 
It is not too clear to me what that s&w is chambered for. That spec sheet in your link says .223, and that is a little odd. Other places on the web, I see S&W ARs that were specified as .223-5.56. I think you had better call the factory an see exactly what it is you ordered. They probably make it both ways, depending on how the customer orders it. I am sure that S&W knows the difference, and would have stated .223-5.56 on the spec sheet, such as bushmaster does.

.223 chambered is for highest accuracy, but you have to use .223.

.223-5.56 chambered is for universality with buying ammo (can probably use ANYTHING, except maybe old lacquered steel cased foreign stuff), but will have less accuracy when using .223 in it.
 
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If you buy an upper chambered for .223 wylde, you can shoot both with no worries.

This is correct.

If its chambered for .223 then it can't use 5.56. Says in the article above that 5.56 is 60,000 CPU and .223 is 50,000 CPU. So this is telling me that a rifle chambered for 5.56 can handle both 5.56/.223 and a rifle chambered for .223 cannot handle 5.56 mm. Am I getting this right??

You are correct about the .223 (Remington), but cricco is pointing out the .223 Wylde chambering. This chambering is designed to work with both .223 rem and mil-spec 5.56x45 ammunition.
 
223?

is this an uban ledgen or is there bases for fact.the 5.56 has a 77gr bullet as the latest bullet the old ones were 55 gr.if the bolt gun wont take 60,000.
then it would be bad for 50,000.this sounds like the 308/7.62 argument.I wish some one would get the correct facts and post them.plenty of people are using 7.62 surplus in commercial 308 rifles.[rolleyes]
 
is this an uban ledgen or is there bases for fact.the 5.56 has a 77gr bullet as the latest bullet the old ones were 55 gr.if the bolt gun wont take 60,000.
then it would be bad for 50,000.this sounds like the 308/7.62 argument.I wish some one would get the correct facts and post them.plenty of people are using 7.62 surplus in commercial 308 rifles.[rolleyes]

The 77gr 5.56 round is the MK 262 Mod 0 & 1. If I remember correctly it requires a modified upper receiver for use. They were originally designed for the SPR or SDM M16's. So no, its not a urban legend.
 
I believe on AR15.com under ammunition you will find all the answers you seek.
My information is that 223 is good in 5.56 but 5.56 is not good in .223. This is due to the tolerances being tighter on .223 than they are on 5.56 and because 5.56 is a higher pressure round this could cause an over pressure situation.
 
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I was on the phone with S&W retail today. According to the very helpful salesperson tthey don't recommend using 5.56 in their AR type rifles that specify .223.
 
I've posted this type of stuff numerous times.

.223 ------------ 50,000 psi SAAMI
5.56mm M855 ---61,000 psi Mil-C-93989C 1994

If you have a .223 rifle and you shot the piss out of it, guess what? It's now a 5.56mm chamber. As the previous poster said. It's the throating that is the major difference.

.308-------------- 62,000 psi SAAMI
7.62mm M80-----50,000 psi Mil-C-60896A (AC)

Shooting NATO Ball in a SAAMI .308 chamber is ok.

B
 
I've posted this type of stuff numerous times.

.

If you have a .223 rifle and you shot the piss out of it, guess what? It's now a 5.56mm chamber. As the previous poster said. It's the throating that is the major difference.



B

So Wrong!!! [crying][crying]
You need a new hobby. Be Serious! So shoot a 7.62x51 and make it a .308? Your resoning is FU. You intend on burning the throat!
 
If its chambered for .223 then it can't use 5.56. Says in the article above that 5.56 is 60,000 CPU and .223 is 50,000 CPU. So this is telling me that a rifle chambered for 5.56 can handle both 5.56/.223 and a rifle chambered for .223 cannot handle 5.56 mm. Am I getting this right??


If it's chambered for .223 wylde, it can shoot either.
 
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