223/5.56

[joebogey]

As you know I just bought a 223. Every once in a while, I'll shoot surplus in my 308, but I see so many folks saying you shouldn't shoot surplus in the 223.
What's the general consensus here?
Surplus a bad idea, or OK in moderation?
It's just that I see so much ammo listed online as 223/5.56, how do you discern which it is?

[tammons]

I think this is correct, but you should confirm first.

5.56 nato runs at higher pressures but IMO its not a big deal in a bolt gun.

More importantly the shell is a hair longer, like a few thousanths or something like that.

If I remember right, a 5.56 nato go gage is the same as a 223 no-go.

A 5.56 nogo is the same as a 223 field gage.

I guess what I am saying is you could set your barrel heaspace for a 5.56 nato and shoot away.

It might work through a 223 headspace, but you would be running it a basically zero headspace which is not good. Not even sure the bolt would close easily. You do not want a pinched bullet !!

If you headspace your rifle for a 5.56 nato you can run .223 through it, its just sloppy.

Certain chambers will shoot both, like a wylde I think. Not sure how that is different from a 223 or a 5.56 nato chamber.

Better confirm all of that before you start trying it out. Dont want to blow up your gun.

[Fjold]

5.56 Nato is loaded to higher pressure (62,366 psi) than the 223 Remington (55,000 psi) and the throat (leade) is longer. In some 223's the longer 5.56 Nato rounds will seat the bullet against the lands of the barrel. This will amplify the already higher pressure and could lead to dangerous pressure levels.

In your 308 Win the surplus 7.62 Nato is safe to shoot because the Nato pressure specification for 7.62 ammo (50,000 psi) is lower than the commercial 308 Win SAAMI spec (62,000 psi).

Here's a drawing showing the difference in the throat dimensions for the 223 and the 5.56:

http://img.photobucket.com/albums/v214/Fjold/Chamber.jpg

[Eric in NC]

5.56 Nato is loaded to higher pressure (62,366 psi) than the 223 Remington (55,000 psi) and the throat (leade) is longer. In some 223's the longer 5.56 Nato rounds will seat the bullet against the lands of the barrel. This will amplify the already higher pressure and could lead to dangerous pressure levels.




All that is accurate, but I have never had (or seen or heard of) a problem with firing NATO 5.56 in a strong 223 bolt gun (like a Savage) that is designed for high pressure cartridges.

I have seen problems from folks doing it in H&R Handi Rifles (usually just case sticking) and in 223 (not 223 Wylde or 5.56) chambered ARs (ruptured cases - bad day!).

Use your own judgement - SAAMI says don't do it, but like I have said - never saw a problem in a bolt gun.

Now as Fjold said - commercial 308 in a 7.62 CETME or Indian Enfield is a mix that can be quite dramatic!

[tammons]

Go to yahoo.

Search for "223 vs 5.56 nato"

About the 3rd line down is a link to a pdf an ar15.com that has the differences in the chambers.



Looks like the shoulder is in the same place so no problem there, but the chambers are different, so whoever told me that about the go gages was full of it. That was a questions asked to a AR15 barel maker if it could handle both 223 and 5.56 nato.

Maybe what he was trying to say was of you headspace a 223 with a 5.56 nato go gages you are okay.
Not usre on that though.

From what I have always read you should not fire a 5.56 nato round out of a 223 chamber although people do it.

223 in a 5.56 nato or wylde chamber is okay.

That said if the problem really is only the freebore and you have a barrel that has a long freebore like a savage usually does it would be pretty easy to find if a nato round will be into the lands on your rifle.

Geez, I have bought 22-250 factory ammo that was jammed into the lands and that has to be a heck of a lot worse condition than a 223 or 5.56.

[brianinca]

I've shot a lot of 556 NATO in both a single shot break action SASS for a 1911, a Mod 70 Winchester carbine, and my 2 Savage 223's. I like the LC brass for reloading and I bought a lot of the XM193 back in the 90's when it was cheap. I've also shot a couple hundred rounds of M855 I bought 3-4 years ago when it was cheap. There was a time it was cheaper buying LC ammo than new Winchester brass.

As someone mentioned with commercial 22-250, there's enough variability in what you get in the box anyway that it verges on splitting hairs unless you have an edge condition to start with. I gave away a box with 17 rds of high $$ Federal Fusion 270 WSM, it was SO hot I had a stiff bolt and the ejector shaved off part of the case head, let alone left a mark.

As for edge conditions, I wound up giving away an M1916 Spanish Mauser (7mm Mauser carbine converted to 762 NATO) - even shooting SA surplus 762 NATO, it just made me nervous, and it was not an accurate beater to begin with. The bubba'd Ishy I'm working on right now, on the other hand, is a pretty sweet rifle - that will be shooting 762 NATO and handloads, not commercial 308.

Regards,
Brian in CA