308 vs 7.62 Nato

Discussion in 'The Ammo & Reloading Forum' started by WILD CAT, Jul 29, 2009.

  1. WILD CAT

    WILD CAT New Member

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    I am really puzzeled. I have been considering purchasing a bolt action rifle in 308 cal. for two reasons; the first is the well deserved respect for this caliber and the second is the possibility of feeding it with military 7.62 hardball for practice, which is abundant where I live.

    Some shooting friends, advised me not to do because I would confront extraction difficulties. I do not understand what to believe. In Lyman's 47th reloading Handbook pages 273 to 275, both calibers 308 Win. and 7.62 Nato indicate that it is the same caliber. I am really astonished. Some said that the venezuelan made cases do not contract or reduce diameter enough after firing for easy extraction. Others consider that the military 7,62 ammo is far hotter than the 308 because it is used in machine guns and automatic rifles (FAL).

    I really desire to buy a rifle in 308, if it would handle the 7.62. very abundant here, costing next to nothing. I don`t mind reducing the powder charge. I am a reloader. What do You think?
  2. JLA

    JLA Well-Known Member

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    it is indeed the same cartridge. the 7.62 nato round is loaded to around 55000 psi and the .308 win cartridge is loaded to around 65000 psi. if you have a rifle proofed for the .308 win. then you are safe to fire both. i have fired .308 from a 7.62 chambered rifle but it maked me nervous to do so.
  3. WILD CAT

    WILD CAT New Member

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    JLA,
    I think I did not explain myself properly. If I get a rifle in 308, I would mostly fire 7.62 Nato in it. So do You think There would be extraction or other kind of problems, considering the rifle is in good condition? please help.
  4. glocknut

    glocknut New Member

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    Oh... So some of the military surpluss rifles that have 762 nato marked on them are not suited for regular 308 ammo like the soft points and such?

    mike
    gn
  5. Mac0083

    Mac0083 New Member

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    Slightly off topic, but related: I have always heard and read that a 5.56 will chamber into a .223 rifle, (because they are the same size cartridge) but the 5.56 will eventually blow blow up the rifle, because it was designed for civilian .223 ammo. But a 5.56 rifle can handle both the 5.56 and .223 because it was designed for the hotter, more powerful military 5.56 round.
    So JLA, are you saying that civilian .308 is actually hotter than military 7.62?

    WILDCAT, if your rifle is designed for the hotter of the two cartridges, then you can fire either. ( but I don't know which is hotter)
  6. Bindernut

    Bindernut Well-Known Member

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    That's correct gn. The exterior case dimensions are identical, but the .308 max pressure is 65,000 as opposed to 55,000 for the 7.62x51. A max load .308 fired through a rifle marked as 7.62x51 will be hotter than what the rifle was designed for and will eventually beat the gun loose.

    A good example of this would be all those reworked Mexican/Spanish Mausers in 7.62x51. These are old rifles and 65000 would be hot enough to either beat the snot out of the gun or worse yet, grenade it. Same thing goes for older semis (like the CETME) too...the hot .308 loads will eventually damage the gun.

    7.62 in a .308 = okay
    .308 in a 7.62 = not okay
    Last edited: Jul 30, 2009
  7. JLA

    JLA Well-Known Member

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    thanks binder... couldnt have elaborated any better myself...;)
  8. WILD CAT

    WILD CAT New Member

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    From the valuable information You have given, I think I'll buy a good quallity 308. Thank You all.
  9. Popgunner

    Popgunner New Member

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    You would be safe to buy a rifle marked for .308 Winchester & fire 7.62 NATO ammo in it. 7.62x51 NATO ammo has a max pressure of 49,700 psi (usually called at 50,000 psi). SAMMI max pressure for the 308 Winchester was for years listed at 52,000 psi. Then that pressure max was raised to 62,000 psi.

    One thing to remember is that rifles such as the Spanish Guardia Civil 1916 rifles were tested at NATO pressures & approved for the NATO cartridge-not the CETME pressure which is even lower. I have one of these 1916 rifles & it's been reported that firing lots of .308 win ammo in them will eventually bend the bolt locking lugs enough to stop the gun from firing. I load light loads only for it.

    Another thing to remember is that 7.62 NATO cases are(edit:can be) THINNER than commercial brass-the opposite of the norm of military brass being thicker than commercial brass. Loads using NATO brass at max .308 Win levels should be reduced by at least 2 grains.

    I have recently bought a Savage rifle in .308 Win that I've shot NATO ammo in & gotten very good groups with it.
    Last edited: Aug 15, 2010
  10. gdmoody

    gdmoody Moderator Supporting Member

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    I have a problem understanding something about this. A while back, I bought a Mossberg .308 rifle. At the same time I bought 50 rounds of surplus 7.62X51 NATO ammo. After I fired something like 6 rounds, the extractor busted. I sent it back to the factory where it was repaired. The second time, I fired something like 9 rounds when the extractor broke again, and again I returned it to the factory for repair. Second time back, I traded the rifle in for something else.

    My friend who owns the gun shop, where I bought the Mossberg and the ammo, told me that he thought the problem was that the ammo was too "hot" to be fired in the .308 rifle. How can this be so if you are saying that 7.62 NATO can be fired in a .308 without any problems??

    I recently bought a Remington 700 VTR in .308 and I am afraid to fire this surplus 7.62 ammo through it. I have no problem shooting it through my L1A1 and that brings up another question, can I shoot commercial .308 through the L1A1!??
    Last edited: Aug 1, 2009
  11. Popgunner

    Popgunner New Member

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    Mr Moody

    NATO ammo is carefully watched to make sure it stays under the 49,700 psi limit while recent commercial ammo in 308 Win is allowed to go as high as 62,000 psi so I don't know how your friend is blaming the NATO ammo being too hot for breaking your extractor. I would more suspect a headspace issue.

    I have an M1-A rifle marked on the barrel 7.62x51 made by Springfield Armory that I was a little hesitant to shoot 308 Win in so I called Springfield & got their dealer rep Dawn. She told me that the M1-A/M-14 was designed (as your L1A1 rifle was) for the 7.62 NATO round but that all of their rifles would handle 308 commercial ammo just fine. She also said they are now marking their rifles as "308 Win" to avoid confusion.

    I don't know what the official word is on the L1A1 shooting .308 commercial ammo but lots of folks are adjusting the gas down & using it in their L1A1's.
  12. Alpo

    Alpo Well-Known Member

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    Many years back (early 80s) I bought a case of PMC 7.62 NATO ball. I planned to shoot it in my 308 bolt gun, since, as everyone knew, 7.62 and 308 were the same round.

    So I’m out with some friends. One has a Remington 788. One has a Mossberg. 800? Mossberg bolt, anyway.

    One guy shoots. Bolt handle comes up but bolt won’t move back. We had to drop a cleaning rod down the barrel and tap on it to break the bolt loose.

    Other guy shoots. Bolt handle won’t move. Once we tap the handle up the bolt moves back freely and ejects the round.

    Both of these guys decide they don’t want to shoot any more of that stuff.

    I shoot. Humongous muzzle flash in my scope. I work the bolt, case ejects, no problem. I laugh at them. “That’s what you get for using them cheap guns. If you had a good gun, like my Steyr, you wouldn’t have a problem.” At shot number three, one of the crosshairs fell off my scope. Redfield widefield. Good scope.

    I eventually gave the rest of the case to my brother, who shot it in a Springfield M1A. He, apparently, had no problems. But it sure seemed overloaded to me, and I was afraid to shoot it anymore.


    So, gd, it wasn't just you that had pressure problems.
  13. Archie

    Archie Member

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    .308 Winchester and 7.62x51 NATO are the same cartridge dimensionally. Military rifles chambered in 7.62x51 are generally chambered 'looser' than commercial rifles to insure reliability of chambering. So rounds fired in military chambers require a little more resizing - BUT the same resizing die does it and I've never had a problem in that regard.

    The NATO round is a lower pressure round. So, barring some really unfortunate factory loading mistake, the NATO round isn't going to blow up a regular commercial rifle - barring some really unfortunate rifle manufacturing mistake. (I deal with lawyers too much; I over qualify everything!)

    Having all that in mind, look at the cases and rifle designs.

    Some surplus and Wolf, et al, ammo is made from steel cases and other brass alloys that may or may not be as ductile and friendly to use as commercial rifle brass. It (the surplus stuff) may tend to stick in chambers more than commercial brass. Some surplus and Wolf, et al, ammo is somewhat more 'vague' in dimensional discipline; so it may stick more.

    I'd bet on a stuck in chamber case to break an extractor sooner than on overload.

    The bottom line is, "You're on your own". Check out the ammo you shoot and just understand that cheaper ammo is just that, cheaper.

    Carry on.
  14. Popgunner

    Popgunner New Member

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    Archie
    You make some very good points.

    Something to remember is that not all "surplus" ammo is NATO ammo. NATO ammo is usually marked for year of manufacture, plant & also a circle with crosshairs.
    The worst 7.62x51 (but not NATO) ammo has been that produced by India & it has actually blown up several rifles. Everyone & their dog produces 7.62x51 but not all is NATO & that means it's a crapshoot. It pays to be sure what you're buying.

    The sticking issue you had was most likely not with NATO ammo. There is no more closely monitored ammo that I know of. Muzzle flash is not usually from overloaded ammo but lighter loads of ball powder. Shorter barrels can also help produce muzzle flash as in the Mosins. Sticking of re-loaded NATO cases is a possibility as the brass is thinner than with commercial cases-the reverse of normal when comparing military brass to commercial. Another way to identify NATO ammo is that it's all BOXER primed. If it's berdan primed it's not NATO but some kind of crapshoot 7.62x51.
  15. WILD CAT

    WILD CAT New Member

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    Popgunner, I had the impression that the 7.62x51 or Nato, was the denomination of a uniform caliber, but your post indicating that not all 7.62 are Nato standard means there are risks firing them in 308. What do You think?
  16. Bindernut

    Bindernut Well-Known Member

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    I tend to think the same way that Popgunner says in his post...Not all 7.62x51 is loaded to NATO spec. If it says NATO, then it should pressure out to the NATO limit...but I'd be cautious with some of the oddball country of origin ammo.

    Alpo's mention of some hot PMC "NATO" stuff makes me think of pretty much every box of PMC I ever bought. I never had a rifle to run any of their 7.62 through but I have bought PMC in several other calibers. Every one of em had either really lousy brass or they were really hot...or both. In one instance, I bought a bunch of PMC 6.5Swede because that's all I could get at the time...I fired about 20rounds through a very clean & tight M96 that would handle Norma or W-W just fine. With every round I got more nervous that the rifle was about to come apart. Several cases had near head separations and the primers were very flat. I quit using that stuff and pulled them apart to salvage the brass & bullet and junked the powder charge they were using. I also scrounged harder for W-W stuff again. The PMC brass didn't last worth a hill of beans either, even with mild handloads they only lasted for 3 or 4 loadings.
    So I'm not sure if you can blame PMC for running higher than normal pressure or if they just had cheap brass. Either one could've caused the sticky bolt problems he experienced with his 7.62 NATO ammo.
  17. gdmoody

    gdmoody Moderator Supporting Member

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    After reading the posts here and LD's post about his new PTR-91 in the Large Bore/Small Bore Rifle/Shotgun forum, I now understand the problem with the 7.62 vs 308 ammo that I mentioned earlier. It was not the ammo's pressure it was the "gunk" used to seal the bullet that was breaking the extractor. Thanks guys!!
  18. WILD CAT

    WILD CAT New Member

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    GDMOODY, as far as I know, the Gunk or sealer of the bullet does not make contact with the extractor, so how does it effect the extractor. I have a K98 Mauser that I treasure and most of the rounds I intend to use now conme with some kind sealer of the bullet. Could You please give me some more information?
  19. JLA

    JLA Well-Known Member

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    If you fire a .308 buy either .308 commercial ammo (i.e. remington, hornady, federal, winchester, etc...) or look for the crosshairs stamped on the headstamp of '7.62X51 NATO' dont buy NATO ammo if you cannot first verifly that it is indeed NATO spec, and ALL NATO spec ammo bears crimped primers and the crosshair stamped in the headstamp... FYI, some of that foreign mfg. ammo was intended for machine gun use, or so I read. That explains why its much hotter than it should be...
  20. K.L. Cramer

    K.L. Cramer New Member

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    I own and shoot two Spanish built mausers. (1916 Short rifle) chambered for 7.62x51mm, One was modified by the Spanish into the FR-7 configuration. I download the NATO ammo (mfg. in South Africa) by removing 5 grains of the milsurp powder and replacing the bullet with a 123 grain Sierra. I do NOT shoot .308 Winchester or NATO ammo as issued. Since these rifles were designed around the 7x57 mm mauser cartridge which has a much lower chamber pressure than the .308 Winchester and the NATO round, the rifles are almost 100 years old, they have a two lug bolt system and the recievers are made of softer steel than are the FN and German made rifles, and primarily because I have a severe allergy to death and pain. A word to the wise, these rifles were "rode hard and put away wet" by the Spanish military, and are being sold mostly by unscrupulous dealers. CAVEAT EMPTOR!!!!
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