Sorry for the noob question. What is the difference between 5.56nato and .223?

[get_armbarred]

I don't know the difference between 5.56nato and .223? Same with 7.62nato and .308? Is there a difference?

 

[Bunnykid68]

.223 Remington - Wikipedia, the free encyclopedia

Read this

 

[Stschil]

Though not well versed in such things, I can tell you that the chamber pressure of the 5.56 is higher than the .223. Burn rates and powders, etc.
The .223 can be fired using a rifle chambered for 5.56 with no ill effects, the converse is not true for 5.56 through a rifle chamber solely for .223. It could, in fact, be potentially devestating, both to the rifle and the shooter.
I would suppose the same would be true in the .308 VS 7.62.

 

[get_armbarred]

Thanks that clears it up for me

 

[Mr Evilwrench]

Isn't .308 hotter than 7.62x51?

 

[Zombiekilloftheweek]

The main difference i know is the price. 5.56 is usually alot more expensive and i can only find it in 20 round packs. 223 is cheaper and easier to find in bulk.

 

[Bunnykid68]

The main difference i know is the price. 5.56 is usually alot more expensive and i can only find it in 20 round packs. 223 is cheaper and easier to find in bulk.

I can find them for the same price at Ammoman.com.
You can fire .223 out of a rifle designed for 5.56.
You should not fire 5.56 out of a rifle that is designed for .223

 

[jlm223]

This is a good read, helped me. 223 Rem + 223 AI Cartridge Guide

 

[Freedom_Bound]

The chamber pressures are different.

 

[lovemywoods]

Though not well versed in such things, I can tell you that the chamber pressure of the 5.56 is higher than the .223. Burn rates and powders, etc.
The .223 can be fired using a rifle chambered for 5.56 with no ill effects, the converse is not true for 5.56 through a rifle chamber solely for .223. It could, in fact, be potentially devestating, both to the rifle and the shooter.
I would suppose the same would be true in the .308 VS 7.62.

The first part of your answer is spot on. However, it's the reverse for the .308 vs. 7.62. You can shoot 7.62 out of a .308 with no problem, but a .308 round shouldn't be fired in a 7.62 chamber.

 

[Stschil]

The first part of your answer is spot on. However, it's the reverse for the .308 vs. 7.62. You can shoot 7.62 out of a .308 with no problem, but a .308 round shouldn't be fired in a 7.62 chamber.

Thanks for squaring me away on that. I was not sure (obviously). Glad someone helped answer the rest of th OP's question.

 

[Mr Evilwrench]

The main difference i know is the price. 5.56 is usually alot more expensive and i can only find it in 20 round packs. 223 is cheaper and easier to find in bulk.

What are you talking about? I always buy military 5.56x45 in case quantities, M193 or SS109. I don't think I even have any .223. Put another 1000 on strippers a couple of weeks ago.

 

[superjoe76]

I can find them for the same price at Ammoman.com.
You can fire .223 out of a rifle designed for 5.56.
You should not fire 5.56 out of a rifle that is designed for .223

This. And you can shoot 7.62 in a barrel chambered for .308 but not the other way around.

5.56/7.62 military grade
.223/.308 ciivilian grade.

I bought a bolt rifle chambered in .308 and an AR chambered in 5.56 so I can shoot what I want.

 

[Aszerigan]

You're correct about the chamber pressures being higher, but one of the most important differences is the wall thickness of the case. 5.56mm cases have thicker walls = lower internal volume = higher pressure levels when loaded with the same loads as .223.

A 5.56mm will pressure test at about 2000psi higher than a 223 loaded with comparable powder.

 

[HeadlessRoland]

throat lead is slightly different too. 5.56 is about half over again as hot as .223 according to saami specs if i recall.

 

[Aszerigan]

throat lead is slightly different too. 5.56 is about half over again as hot as .223 according to saami specs if i recall.

True, it's harder on the brass to shoot it. It's not 1/2 again as hot though, it's actually 36,000psi vs 38,500 or so.

 

[Leo]

Aszergian, I agree with you on the pressures, that sounds reasonable, and I am too tired to look up the Sammi specs. Where did you get your info on thicker case brass between military over commercial brass? I tried to type in the findings of my experiment, but my data must be too long, as the software keeps telling me I am not permited to add the post. I may have to put my experiment in part at a time. I was not able to prove military brass is thicker by weight, volume or measurement, even using good sound scientific and statistical systems.


M2 ball ammo is definately thicker than commercial 30-06, you can feel the weight with your hand. 7.62 X 51 brass is some thicker than commercial .308, and it shows easily on a scale. the M-16 ammo is a different story

 

[Aszerigan]

Aszergian, I agree with you on the pressures, that sounds reasonable, and I am too tired to look up the Sammi specs. Where did you get your info on thicker case brass between military over commercial brass?

It was a published torture test between the .223 and 5.56mm brass. Starting with new brass, before the test, they sawed a few lengthwise and measured case thickness at the base, body, shoulders and neck. I don't remember where the article was, most likely in a gun magazine. I'm sure I could find it if I really looked for it.

If you have different information, please share. I'm not averse to be corrected if I'm wrong about it.

 

[Leo]

I'll write it some at a time so it will not kick me off.
Not a correction, but an experiment
I took 5 or 6 cases from different brands, ie: LC, LC NATO cross, WWC, Federal, Remington, Winchester, PMC etc I figure this would be a good sample
Next is my system

 

[Leo]

1) tumble them all night to eliminate soot variations
2) lube, size and deprime
3) trim to exactly the same length
4) weigh all the cases
5) After priming with the same primer, Fill them to the top with BLC-2 powder because of small consistant granuals, striking level with a razor blade
6) weigh all the powder charges
7) section a couple from each group with a band saw in a fixture to make all the lengthwise cuts the same

My findings will be the next post