7.62 .308 are'nt they they same?

Discussion in 'The Ammo & Reloading Forum' started by madbuck22, Feb 26, 2011.

  1. madbuck22

    madbuck22 Member

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    i thought 762 and 308 are the same round. don't know much tech on ammo but i want to start reloading in the next couple months. 30-06,308, 223-556 same ? i can tell from some of the stuff i've read alot of u know a **** load about reloading. i'm new here so u might get some stupid ?'s from me but i really want to learn as much as i can from people who have been there done that. thanks guys.:D
  2. RandyP

    RandyP Member

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  3. madbuck22

    madbuck22 Member

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  4. steve4102

    steve4102 Former Guest

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    The link to Yahoo answers "best answer" is incorrect. The 7.62 does NOT have an operation pressure of 50,000psi. it is 50,000 CUP which is a hell of a lot different than psi.

    Here this explains it better.

    http://www.smellysmleshooters.net/ammopressure.htm
  5. RandyP

    RandyP Member

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    In truth I just grabbed the first link of the zillion or so that came up from a quick google search pointing out the differences in the ammo. One of the hazards of believing ANYTHING you read on the internet - LOL

    I think we can however both agree that the two calibers are not the 'same'? Which was the whole point of the OPs question.
  6. ozo

    ozo Well-Known Member

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    A simple way to stay safe is easy, if the caliber is labeled a different
    caliber, it is a different caliber.
    This difference between the .308 and the 7.62 can further be seen
    why a specific caliber has it's specific caliber by comparing the
    .38 to the .357 where there is only a tiny bit of length difference
    and the case a bit thicker, but different internal pressure. You wouldn't want
    to shoot a .357 in a worn .38 if it were to fit. Maybe not a good comparison,
    but one nonetheless. It will keep you safe though.
  7. jlloyd73

    jlloyd73 New Member

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    My .308 says it will shoot 7.62x51 I believe.......but there are several different 7.62 rounds...thats the part I cant figure out.
    Last edited: Feb 27, 2011
  8. WILD CAT

    WILD CAT New Member

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    The 308, and the 7.62 are definitely the same. Commercial 308 ammo however has an advantage over military fodder. I bought a factory new Savage 110, I didn't fire it, because I ususally get all the information I can find before I try a new gun. The advantage of commercial 308 is its uniformity. In my rifle club most of the members keep the 308 which is quite expensive, for serious work like competitions and hunting. The military 7.62 is very abundant here in venezuela and really a cheap product of the official CAVIM arsenal. It chambers smoothly, and high on the precision scale. However extracción of the empty shell is sometimes difficult because according to my shooting pals, The brass has a somewhat smaller capacity resulting in a higher pressure. The higher pressure causes the shell to over expand and the fired brass is not reduced enough to make extracción easy. So most of our club members who can´t afford shooting 308, pull out the bullets, reduce the powder charge and reseat the bullets having reported satisfactory results.

    I intend to try the new rifle using the same proceeding starting with low pressure loads and go up carefully. once done I´ll be pleased to share the results.
  9. WILD CAT

    WILD CAT New Member

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    The 7.62 NATO official round is in fact the equivalent of the 308 win. It is the most used round by the military in weapons ranging from the German G3 assault rifle and the FAL (Fusil Automatique Leger) to the fabulous modernized airborne Gatling.

    If You intend to use it in a rifle, don't forget that it is produced in many countries and for different purposes and that implies some minimum differences beween one production and other. Those differences are rarely noticed in chambering the cartridge because the outside dimensions of the 308 and the 7.62 are nearly identical. The main differences might be the inside capacity of the case, the flexibility of the brass, the powder charge and the pressure. Many manuals indicate that the 308 generates more pressure that the 7.62. Be careful The 7.62 Nato is nominal in this aspect which does not mean that all 7.62 are uniform. I suggest You try the procedure I described in my former post. Also don't forget to weigh the bullet and its charesteristics, check in at least 2 or 3 manuals starting starting with the lowest suggested load minus 10 % of the listed charge.
    That's all I know. Good luck.
    CAT
  10. medalguy

    medalguy Member

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    Actually if you are referring to the caliber .308 and 7.62, yes they are the same. .308 is the decimal equivalent of the metric 7.62mm. Now, if you are referring to a specific round of ammo, then they may be different. In 7.62, you can have a 7.62 x 51 which is essentially the same as .308 Winchester, or 7.62 x 54R which is an old Russian rifle round. Then there's 7.62 x 39 which fits the AK47 rifle. And there's the 7.62 x 25 Tokarev round which fits a pistol.

    The caliber is the measurement of the diameter of the bullet. That's different from the loaded ammunition description. A 7.62mm bullet can be fired in a .308 rifle and vice versa. Same diameter.
  11. polishshooter

    polishshooter Active Member

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    Actually the .308 Winchester was developed from and AFTER the 7.62 NATO round was developed. The NATO round was developed and adopted in the 50s, the .308 Winchester Round was developed in the late 50s and became commercially available in the early 1960s.

    The SAAMI specs for the .308 are different from the NATO Standard.

    I own a 1964 Ishapore MKIIA 7.62 Enfield, and I would NEVER shoot commercial .308 ammo in it, but keep a good supply of either British or South African 7.62 NATO around for it.

    If you own one of the 1916 Guarda Civil small ring mausers available (Again!:p) advertised as ".308 WInchester" I would be VERY careful, especially since it was PROBABLY rechambered originally for the 7.62 CETME round, which is another animal altogether, although it TOO is "dimensionally identical" to both the 7.62 NATO and the .308 Winchester.


    http://www.surplusrifle.com/shooting2006/308vs762nato/index.asp
  12. al45lc

    al45lc New Member

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    SAAMI does NOT list the 7.62 NATO and the .308 Winchester as an UNSAFE cartridge and firearm combination.
    If in GOOD condition, it should be safe.
  13. WILD CAT

    WILD CAT New Member

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    I believe Polish shooter that one of us, probably me, got a bit confused. Two main reasons for the adaption of the 7.62 as NATO official round by the american forces, is that the former 30-06 could be easily sized down which reduced its weight and that the the loss of speed about 215 fps wasn't very significant. Now before the U.S. approved the switch, it had allowed the commercial 308 for civilian and hunting use. So when the 7.62 Nato was adopted, the 308 win was already in the market. excuse me for not having at hand the details. Anyway I could be wrong.

    CAT
  14. hogger129

    hogger129 Active Member

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    7.62mm = .308". It's a measure of the diameter of the cartridge.

    The difference is in the length of the cartridge. There is .308 Winchester, .30-06, .300 Win Mag... These are all .308 caliber and 7.62mm. But the cartridges are different lengths.

    As far as NATO cartridges go, NATO cartridges are not the same. The brass is thicker and the chamber pressure is higher. That's why you can't go and shoot 5.56x45 NATO out of a gun made for normal .223 Remington.
  15. madbuck22

    madbuck22 Member

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    so if you shoot 556 in a ar style 223 will it be over gased. or vise versa 223 in a 556 will it be under gased and maybe jam or somthing like that same with 308 and 762?
  16. WILD CAT

    WILD CAT New Member

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    Yes, because in some rifles there is a space called the "Leade", between the mouth of the chamber and the rifling. In military rifles like the M16 the Leade is a bit deeper than in some sport guns like the Thompson Center and allow a margin of pressure and easy functioning of the 556. or the 223 safely. On the other hand, the Leade in the Thompson Center is shorter and I have seen some with extraction problems when firing 556 ammo. I would prefer to play it safe and use only 223 in civilian rifles unless the manufacturer indicates that you can use the 556. I always remember that military ammo for the 556 and the 7.62 are manufactured in many countries and that the specifications of the round are nominal. An example: On page 629 of The book "Small Arms of The World" 1977 edition,The specifications of the 7.62 Nato are the following: Complete round weight 375 grains; Bullet weight 150 grains; Propellant weight 48 grains. Etc. This is definitely nominal especially for reloaders. Although the most widely used by the military factories is the BLc2., I can't be sure that all components used are the same.
  17. Archie

    Archie Member

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    The .308 Winchester round and the 7.62 (x51) NATO round are dimensionally identical - externally at least. U. S. military 7.62 NATO brass is thicker for use in automatic weapons and the chamber volume is reduced.

    Chambers for U. S. military rifles and machine guns firing 7.62 NATO are essentially the same as civilian/sporting rifles in .308 Winchesters, but are intentionally cut 'looser', towards the larger end of the tolerance spectrum. This is to allow fired cases to be extracted with less pull on the extractor and case rim. The idea is to make the weapon function more reliably. The downside is if used for reloading, the brass needs more work to resize. And, as mentioned, the smaller inner volume means powder charges need be a bit lighter; I am aware of no formula to determine how much lighter.

    Cartridges bearing the NATO mark, a circle with an X or + within, are by treaty within the acceptable pressure range for that specific NATO round. By U. S. standards, 7.62 NATO operates at a lower pressure level than commercial .308 Winchester.

    The only other two NATO rounds of which I am aware are the 9x19 NATO and 5.56 NATO. Anyone with specific knowledge please speak up. The 9x19 is a bit weaker than commercial U. S. loadings and considerably weaker than European commercial loadings. The 5.56 NATO, on the other hand - dimensionally identical to the U. S. .223 Remington round - is loaded to higher operating pressures.

    So, are the rounds the same? Sort of 'yes' and sort of 'no'.

    Shooting commercial 308 Winchester ammunition in a U. S. military firearm - primarily the M14/M1A unless you're one of those rich guys who have the odd M60 in the closet - will not blow up a serviceable rifle. However, repeated use of slightly high pressure ammo will wear the firearm out sooner. I know of no catastrophic failures with 'military' ammo in commercial rifles, except for a lot of ammunition nearly sixteen years ago that was intentionally sabotaged - I think had a CVM head stamp - and the odd failure to extract with Wolf steel case ammo.

    The inverse is true regarding .223 Remington and 5.56 NATO. The NATO ammo is hard on civilian guns, but it won't blow up; it'll just get battered and worn sooner.

    The 9x19 NATO can be fired by any pistol so chambered - usually marked 9mm Luger or 9mm Parabellum - with confidence.

    Back to .308 Winchester and 7.62 NATO.

    If one reloads, the difference is merely in internal capacity and easily determined in the normal 'work up' routine. When reloading, one can use commercial .308 Winchester brass for military rifles and use military head stamped cases for .308 Winchester.

    By the way, this question comes up nearly as often as the ".44 Special vs. .357 Magnum" debate. One hears all manner of claims.
  18. madbuck22

    madbuck22 Member

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    hey i appriciate everyones info and opinions, i'm really glad i stumbled upon this place. thanks peeps!
  19. ozo

    ozo Well-Known Member

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    Well Buck,
    If you really mean it, hang around ! And post-post-post !!
    Glad tahavya. :cool:
  20. bluesea112

    bluesea112 Active Member

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    Ok, I found my bat. Where did y'all put that horse?
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