.223 v 5.56

Boredstiff666

Here's a good one to chew over. Apparently there is hardly any difference at all.

https://www.youtube.com/watch?v=BTgGhIcR_Mk

juice1304

the difference is the thickness in the case and the 556 operates at 10,000psi more. there are a couple of other slight differences but thats basically it.

Gorgeousgeorge

juice1304 wrote: »

the difference is the thickness in the case and the 556 operates at 10,000psi more. there are a couple of other slight differences but thats basically it.

So a rifle chambered in 5.56 is stronger than a rifle chambered In .223 as its round is running alot hotter with bigger pressure??

Cass

Wrote this on the exact same topic last year.

The 5.56 is usually made to NATO spec (its why it's called a NATO round) and is usually "hotter" than your standard 223 round and as such it has much higher pressure than the 223.

There are other, subtle, differences. The 5,56 has a slightly different shoulder to the 223, and the freebore or leade on a 5.56 rifle is usually a little more than a 223 rifle.

What that all means. A 5.56 round in a 223 rifle would produce about 15,000 psi more than a 223 round. The round is "longer" than the 223 and hence the free bore is lessened which can increase pressure even more, and because the case (of 5.56) has not the room to expand properly in a 223 all this can lead to catastrophic failure of the rifle. Best case, and by best i mean non life threatening, is the case gets stuck in your barrel, but as a rule it's best to just not shoot them (5.56) in a 223 rifle.

In case all that is TL:DR do you potentially want this:

https://www.youtube.com/watch?v=1g1UjzL55k0

In the reverses (223 in a 5.56) its all the opposite. The 223 has loads of free bore (shorter round), less pressure, more room to expand, etc. Meaning the 223 can be safely fired from any 5.56 rifle. The only issue is most 5.56 rifles are fast twist rate which are designed to fire a very specific bullet (usually 62-64gr with the occasional 77gr thrown in) and so anything other than these bullets will result in poor performance.

Boredstiff666

Cass if it was producing more pressure, wouldnt it be producing more velocity? This was not shown in Paul's video as velocity was more or less the same.

Cass

It can, but there are other factors as per my post above not to mention i found while reloading that there is a point of "diminishing returns". Meaning there is a point where with more propellant you achieve little increase in velocities. Now my experience is with 308, but off the top of my head i remember that when i went above a certain grainage/charge in propellent i got very little in terms of increase in velocity however i did start to get pressure signs such as primer flattening, marks on the case head, stiff bolt lifts, etc.

As i said in my post above, and to elaborate a little, i can put a "safe" round in my rifle and fire it to get a certain speed. I put the same round in another rifle and due to tighter chamber, less freebore, etc. the round produces more pressure which shows itself in stiff bolt lifts, flattened primers and case head markings.

Its why its a bad idea to use reloaded ammo for one rifle in another, even if its the exact same caliber and make. Again i have first hand experience of this while using a round in one of my Savage 308 rifles and then trying it in another Savage 308 i had. Before i'd even fired it the bolt was stiff to close. After firing i had serious trouble trying to lift the bolt and extract the case. It showed the above pressure signs even though i got none of them in my rifle.

Lastly the pressure difference between 5.56 and 223 can be UP TO, but not necessarily always, more than 10,000+ psi. IOW depending on the bullet weight/size the propellant used, etc. there can be little difference or a huge difference.

I have no proof of the following statement but i'd wager that the ammo used in Military firearms are all loaded to a certain charge each and every time but the ammo available for public consumption would not be loaded with either the same charge or same propellant.

My semi auto rifle will fire 5.56 and 223. I stick with 223 because the ammo is more plentiful and available. When i rang Remington about using 5.56 in my rifle they deflected and never committed to a definitive answer as to whether it was safe. I've been told this is a legal issue. IOW they don't want to be liable for saying yes, even though the rifle can use both. As a result my rifle has a slightly longer freebore than a standard 223 rifle (bolt action). It tends to prefer a very specific range of ammo (60 - 69gr only) and most types outside of this range either only work at certain distances or not at all. By not work i mean the group size at 100 yards can go from 3/4" to 2"+.

Here is a thread where a member was sold "223" ammo which was actually 5.56. Got a case stuck in the rifle with stiff bolt lift and extractions. He also found out, about 6 to 8 weeks later, that he now had other serious issues with the rifle which while i cannot say were strictly down to the wrong ammo being used, but wouldn't have helped.

jb88

Would buying a .223 wylde chambered gun not solve all of these problems?

Cass

Yup. So would having a rifle chambered in 5.56.

I don't think it's a problem. I'd imagine 99.9% of shooters use 223 in a 223 chambered rifle, and anything they want in a rifle chambered in 5.56. The only issues i've ever seen, and they number in single digits, was someone buying 5.56 ammo and using it in a 223 but this was down to the RFD not telling them it was actually 5.56 ammo or the shooter not knowing the difference.

Cheap ammo is cheap for a reason. Some is crap (mostly steel case stuff), and others are 5.56 that is sold or marketed as being 223 and at between €4 to €7 per 20/25 rounds people tend to go for it because it's cheap trigger time. It becomes a problem when you're €7 box of bullets damages or destroys your rifle.

Grizzly 45

The 223 Wylde is basically what barrels or guns marked .223/5.56 are.The happy medium of both cals,but isnt an actual caliber in itself.

tudderone

I see SIG have brought out a new round, the 277 SIG. It operates at 80,000 P.S.I ! I wonder how long the barrels will last.