.223 vs 5.56x? and .308 vs 7.62x?

[RichardEdward]

.223 rem vs 5.56 NATO.... .308 vs 7.62.. what are the differences if any.. are they just different names for the same round? can a rifle that shoots one shoot the other? (ie .223 shoot 5.56 and vice versa.. not can a .223 shoot a .308 unmodified.. im dumb but not that dumb)

[Fatcat]

Same cartridges. The military likes to make up their own names for things..

7.62 NATO = .308 Win
5.56 NATO = .223 Rem

[Art Eatman]

The only practical difference between a Remington .223 and a NATO 5.56 is the thicker brass of the NATO case. Either will quite happily shoot in any rifle marked ".223" or "5.56 NATO".

Now, 7.62 is 30-caliber, but there is more than one "7.62", as in the 7.62 x 39 which isn't what you mean.

Anyway, the .308 Winchester and the 7.62 NATO are the same animal, except, again, the thicker brass of the NATO case.

To reload for semi-autos, "Small Base" resizing dies are used, to facilitate chambering and extraction in those rifles. These dies are, I dunno, one or two thousandths of an inch tighter than "real" dies. (Sorry, I'm a bolt-action guy. ) The caveat in reloading with NATO brass is that since the case capacity is somewhat less than with civilian brass, one must be careful not to use maximum loads of civilian-brass style and thus exceed safe chamber pressures.

Hope this BS helps,

Art

[biganimal]

the main reason for the different names are because us dumb Americans cannot understand the metric system of measurement. the military hangs around all them NATO bastards so we must use the metric system or they won't know what WE are using!. maybe it ain't us that dosen't understand!!!



7.62 and 5.56are the bullet diamater in millimeters while .223 & .30 are good ole American inches.

[RichardEdward]

everyone,

i seem to remember someone telling me that some russian rifles can shoot american / nato ammo but not vice versa.. is this true.. ? if so what calibers are we talking about?

[vince weng]

5.56NATO != .223
7.62NATO != .308

physically, they seem to be changeable. However, the pressure is different.

5.56 NATO gets higher pressure than .223.
.308 get higher pressure than 7.62 NATO.

what does that mean?

If you have an old military rifle in 308, you'd better off not using .308 ammo. That is safe.

if you have an old commercial rifle in .223, you'd better off not using 5.56 NATO. That is safe too.


of course, if your firearms are of good quality, you should be ok.

[LIProgun]

While I agree there are pressure differences between .308 Win and 7.62x51mm NATO, I am unaware of any pressure differences between commercial .223 Remington and 5.56mm NATO ammo. vince weng, can you cite a reference for the latter proposition?

[Dean Speir]

While I agree there are pressure differences between .308 Win and 7.62x51mm NATO, I am unaware of any pressure differences between commercial .223 Remington and 5.56mm NATO ammo

Nor am I, LI ProGun!

But on the always contentious matter of .308 Win v. 7.62 NATO, RichardEdward, Art Eatman and FatCat should be advised that they are not the same cartridges. For specifics, see:

.308 Win. and 7.62mm NATO Are Not Identical

As a matter of fact, it turns out that not all "7.62 NATO" ammo is identical, either.

[dZ]

its not about the cartridge, it is about the CHAMBER

one more time:
http://www.thefiringline.com/forums/...threadid=56047

http://www.thefiringline.com/forums/...threadid=15031

TECHNICAL DATA SHEET
http://www.saami.org/unsafe3.htm
UNSAFE ARMS AND AMMUNITION COMBINATIONS

CENTERFIRE RIFLE
In Rifle Chambered For
223 Remington
Do Not Use These Cartridges
5.56mm Military

>>>>>

http://www.fulton-armory.com/308.htm

dumb question i alway thought these 2 ammos where interchangeable but some have told me otherwise whats the
story??? jim

Hi, Jim,

This is a perennial topic, kinda like ".45 vs. 9mm" or "Best Guns & Loads for Deer."

They are not the same.

They are the same.

They are not the same, 'cause the .308 Win was released by Winchester several years before the Army standarized the T64E3 as the 7.62MM.
You'll get an endless discussion of pressure specs, endless because SAAMI and the Ordnance Dep't measured pressure in different, unrelateable
ways. Howver, the chamber drawings are different.

They are the same, 'cause nobody (and Clint's been looking for many years!) makes 7.62MM ammo that isn't to the .308 "headspace"
dimension spec. So 7.62MM ammo fits nicely into .308 chambers, as a rule.

But in some 7.62MM rifles the chambers are long (to the 7.62MM military spec), notably the Navy Garands with 7.62MM barrels. Thus, using
commercial ammo in such a rifle is not a good idea; you need stronger brass. Use military ammo or the best commercial only, e.g., Federal Gold
Medal Match.

Most of the time it's a distinction without a difference. But if you intend to shoot .308 commercial in a military arm chambered for 7.62MM, first
check the headspace with .308 commercial gauges first. You may get a surprise.

Best regards,

Walt Kuleck
Fulton Armory webmaster


Clint, What's the difference between .308 Winchester & 7.62x51mm NATO?

Jerry Kuhnhausen, in his classic Shop Manual (available from Fulton Armory; see the M1 Rifle Parts & Accessories or M14 Rifle Parts and
Accessories Pages under Books) has published a somewhat controversial recommendation concerning .308 Winchester and 7.62x51mm NATO
ammo, headspace & chambers. I broached the subject with him some months ago. He had his plate full, so we decided to chat on this in the
future. When we do I'll report the results of our conversation.

I completely agree with Jerry that if you have a chamber with headspace much in excess of 1.636 (say, 1.638, SAAMI field reject), you must use
only U.S. or NATO Mil Spec Ammo (always marked 7.62mm & with a cross enclosed by a circle) since the NATO mil spec calls for a far more
"robust" brass case than often found in commercial (read .308 Winchester) cartridges. It is precisely why Lake City brass is so highly sought.
Lake City brass is Nato spec and reloadable (most NATO is not reloadable, rather it is Berdan primed). Indeed, cheaper commercial ammo
can fail at the 1.638 headspace (e.g., UMC) in an M14/M1 Garand. Many military gas guns (e.g., M14 Rifles & M60 Machine guns) run wildly long
headspace by commercial (SAAMI) standards (U.S. Military field reject limit for the M60 & M14 is 1.6455, nearly 16 thousandths beyond
commercial (SAAMI) GO, & nearly 8 thousandths beyond commercial (SAAMI) field reject limit!).

I also agree that 1.631-1.632 is a near perfect headspace for an M14/M1A or M1 Garand chambered in .308 Winchester. But I think that it also
near perfect for 7.62mm NATO!

I have measured many, many types/manufacturers of commercial and NATO ammo via cartridge "headspace" gauges as well as "in rifle"
checks. If anything, I have found various Nato ammo to be in much tighter headspace/chamber compliance than commercial ammo. Indeed,
sometimes commercial ammo can not be chambered "by hand" in an M14/M1A with, say, 1.631 headspace (bolt will not close completely by
gentle hand manipulation on a stripped bolt, although it will close & function when chambered by the force of the rifle's loading inertia),
though I have never seen this with NATO spec ammo. I.e., if anything, NATO ammo seems to hold at the minimum SAAMI cartridge headspace
of 1.629-1.630, better than some commercial ammo!

So, why set a very long 1.636 headspace in an M14/M1A or M1 Garand? It probably is the conflict mentioned above. Military headspace gauges
say one thing, SAAMI headspace gauges say something else, as do the spec's/compliance covering ammo. In a court of law, who will prevail? I
think Kuhnhausen gave all those who do this work a safe way out. However, I believe it not in your, or your rifle's, best interest. Whether you
have a NATO chambered barrel (M14/M1 Garand G.I. ".308 Win."/7.62mm NATO barrels all have NATO chambers), or a .308 Winchester chamber,
keep the headspace within SAAMI limits (1.630 GO, 1.634 NO GO, 1.638 FIELD REJECT). This subject is a bit confusing, and for me difficult to explain
in a one way conversation!

Clint McKee

[RichardEdward]

I am sooooo confused..

[RichardEdward]

thinks for the link..

lets see if i understand it... i can use .223 rem in a weapon chambered for 5.56 NATO but not vice versa

I can use a 9mm luger in a weapon chambered for 9mmNATO but not vice versa

SO if at all possible it would best to get a 5.56 NATO rifle and a 9mm NATO pistol?

[biganimal]

Damn !!! I learn something new every day as a rule and I did here today but I'm not sure what it was !!!!

[Fatcat]

Well, I learned something new today. That's why I love this place!

[RichardEdward]

the other 7.62.. is that the russian version.. how does it play into all this.. (everytime i think i understand this i find something else in a post that throws me for a loop)

[labgrade]

Something else to clear up, or maybe confuse you more ....

Do the inch-to-metric conversion & the numbers don't match (.223" = 5.66mm & .308" = 7.82mm) ... reason being is 'cause metrics are measured to the barrel's groove diameter while the inchers are measured to the lands.

Same actual bullet diameter, but different way of looking at the barrels they're shot in.

People are funny.

[Art Eatman]

1. Note I said "for all practical purposes" they are the same. They are--particularly if you have a bolt-action rifle. And I don't know of any normal-manufacture military semi-auto load which could be "too hot" for a bolt action. Lastly, I never found any sort of ammo my HK 91 wouldn't digest, and the same holds true for a couple of bolt-action .308s I've had. I figure if something chambers without using a hammer, and extracts the same way, it must be what's meant to be there. Aside from headspace I refuse to worry about a few thousandths one way or the other.

2. Berdan-primed cases can be reloaded, but why go to the hassle?

3. The Russian 7.62 is the 7.62X39, or AK-47-and-clones round. (AKS, AKM, I dunno whatall...)

4. Some measurements are across the lands; others are across the grooves. Once upon a time, folks talked of 30-caliber rifles as .3085 inches, rather than just .308. Sorry I don't remember offhand whether that was land- or groove-diameter. I'm at the Austin Public Liberry, not home with the reference books...

[RichardEdward]

i posted the same question on shooters.com and got this reply
"RichardEdward, After I blew my Valmet up I read the owners manual.
In my eagerness to send a few down range I grabbed up some Portugese
ball 5.56 mm and went shootin. About six or seven rounds dowmrange
and KABLAMMMMMMM! The neck and shoulder of a round had seperated
and stuck in my chamber and a new round followed behind, soon to
be followed by the firing pin, on a live round, bolt open, constricted
barrel, you get the picture. The next bullet lodged in the barrel
because the entire force of the explosion exited the ejection port
area. Lucky I can still see, probably lucky to be alive. No real
injury except feeling like somebody threw sand in my face just prior
to socking me. The manual read .223 only, do not shoot 5.56 mm.
The empty deprimed FNN headstamp brass weighed 100 grains! Thick!
Tough! Too tight to feed through the neck of my gun. Lesson learned.
Read and follow the manual! Some .223 chambers will not accept 5.56
mm ammo, particularily if it has brass that weighs al!
most 10% more than average. Kevin "

To view the response in the room, or to reply, go to:

http://talk.shooters.com/room_50/10255.cfm#61179

[Dean Speir]

Some .223 chambers will not accept 5.56mm ammo, particularily if it has brass that weighs al! most 10% more than average.

Um, RichardEdward, where do you suppose that "extra" material is in the military brass?!?

Have you actually thought about this at all, or are you just out there looking for any sort of answer without critically evaluating it?

[BigG]

Another appearance of "the thread that will not die."

[RichardEdward]

i would imagine their could be more brass on the inside of the nato round.. ie the inner diameter of the two are different but the outside are the same.. OR.. the extra brass is on the outside.. ie the inner diameters are the same and the outer are different.. or they could be a different length

could be a problem for lots of reasons.. but the main one i would see is if there is a gap between the case and the chamber somewhere.. a significant gap could allow the pressure to blow out the sides of the case / or back instead of pushing the bullet out the barrel..

what is the deal with people on these gun boards thinking i have some type of alterior motive.??? i get the same crap on shooters.com and assaultweb.com..

im someone with very little experience but an interest (well i used to.. if this is what i have to look forward to if i start shooting more regularly.. i dont know) in learning and participating more

[Bulldog]

3. The Russian 7.62 is the 7.62X39, or AK-47-and-clones round.

And don't forget about the 7.62x54R...

[Art Eatman]

Richard Edward: .223, .308 and .30-'06 military brass is thicker than civilian brass, but the outside dimensions are the same. The case wall is thicker for GI brass. With military brass, the total capacity is less.

I know more about the '06: My pet load of 4064 is 52.5 grains behind a 150-grain bullet. If I put that into GI brass, it flattens primers, indicating more chamber pressure than is actually the wisest thing to do. I might get into difficulty if I used a faster burning powder; 4064 is sorta "forgiving" compared to, say, 3031 or 4895.

The obvious test is to fill a case of each type, and then weigh the charges. For .308 and .30-'
06, the difference is approximately four grains weight of powder, IIRC. Mas o menos...

Hope this nattering helps,

Art

[RichardEdward]

art..

so you are saying that it is ok to use .223 in a 5.56 rifle or vice versa as long at you check to make sure you arent using more powder / or a faster powder than the typical round for that rifle??

[vince weng]

As I said .223 != 5.56 NATO.

Please refer to http://www.reloadbench.com/cartridges/223.html

as you know the inception of M-16. Stoner sited to use fast burn powder (stick powder) for this weapon. Unfortunately, military still used ball powder, therefore, malfunctions (jams) happened because ball powder was dirtier than stick powder. Of course this was corrected.

Although I don't have reloading data on my hands, at least we know that the powder in 5.56 NATO is different from that in commercial .223. The reloading manuals don't mention the differences.

[Art Eatman]

Richard Edward: If you are reloading around maximum charge, use maybe two grains weight less powder in GI brass than in Civilian brass, for the .223. I'll guess it's maybe three grains less weight for a .308, roughly.

A bolt-action rifle won't care about the source of factory ammo, whether it's civilian or GI "surplus". It all will fit--at least the stuff I've bought over the last 25 years has. Heck, same for a Mini-14.

Now, most folks prefer "small base" resizing dies for rifle cartridges used in a semi-auto--mostly for .308, although I guess it's true for the .223; dunno for sure. These dies compress the rearmost part of the cartridge case a couple of thousandths less than the regular dies. This facilitates reliable chambering during a string of fire. Bolt closure on semi-autos is somewhat less positive than for bolt-actions, since it depends on the force of the spring rather than the strength of the shooter and the leverage of the bolt handle.

FWIW, Art