okay; it's been a while since I've been here, and it's probably already been asked before by others, but I need to ask this: can anyone tell me if there's any significant difference between .308 and 7.62? I have an M1A and want to stock up for it. Some say it doesn't matter; others say it does. Springfield told me to use .308 that's within sammi specs, and 7.62 that's mil spec, but I can't seem to find out if the ammo brands that I'm looking at meet those specifications. Very frustrating.
.308 vs. 7.62
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Carne Frio
Member
Here is a link that might help answer your question.
http://how-i-did-it.org/762vs308/chamber.html
And another link:
http://answers.yahoo.com/question/index?qid=20090705154413AAqrYDu
Still one more (scroll way down the page):
http://www.ar15.com/forums/t_6_2/377010__308_vs_7_62.html&page=2
So, they are not the same but are almost the same. I use only 7.62 x 51 in
my military type guns. I shoot .308 and 7.62 x 51 in .308 rifles.
http://how-i-did-it.org/762vs308/chamber.html
And another link:
http://answers.yahoo.com/question/index?qid=20090705154413AAqrYDu
Still one more (scroll way down the page):
http://www.ar15.com/forums/t_6_2/377010__308_vs_7_62.html&page=2
So, they are not the same but are almost the same. I use only 7.62 x 51 in
my military type guns. I shoot .308 and 7.62 x 51 in .308 rifles.
Acera
Member
There are dozens of threads on here about that.............
http://www.thehighroad.org/showthread.php?t=594603&highlight=.308+vs.+7.62
http://www.thehighroad.org/showthread.php?t=435211&highlight=.308+vs.+7.62
http://www.thehighroad.org/showthread.php?t=657834&highlight=.308+vs.+7.62
http://www.thehighroad.org/showthread.php?t=605473&highlight=.308+vs.+7.62
http://www.thehighroad.org/showthread.php?t=673898&highlight=.308+vs.+7.62
http://www.thehighroad.org/showthread.php?t=594603&highlight=.308+vs.+7.62
http://www.thehighroad.org/showthread.php?t=435211&highlight=.308+vs.+7.62
http://www.thehighroad.org/showthread.php?t=657834&highlight=.308+vs.+7.62
http://www.thehighroad.org/showthread.php?t=605473&highlight=.308+vs.+7.62
http://www.thehighroad.org/showthread.php?t=673898&highlight=.308+vs.+7.62
mljdeckard
Member
So....purely from my inability to leave an answered question alone, why is it pretty much the opposite of the rule for 5.56/.223? That the civilian version was made to be more universal than the NATO spec, where for 5.56, the NATO spec chamber will run anything?
Kachok
Member
I have plenty of 7.62 brass, it is quite a bit thicker then my standard 308 stuff, so I work loads for it totaly differently, treating it the same would no doubt spike presures since case volume is reduced. Truth be told though I like plain ol 308 better it is a hella lot easier to resize.
ExAgoradzo
Member
This ought to be a sticky. I'm not ready for this discussion yet, but I know some day I will be. Other priorities now...
Greg
Greg
madcratebuilder
Member
Read this.
http://thefiringline.com/forums/attachment.php?attachmentid=39835&d=1229900860
There is a minor difference in head space spec between .308 and 7.62. Manufacturers set their 7.62 chambers to be safe with either round.
.308/7.62 is head space.
.223/5.56 is the amount of leade, or chamber length vs loaded round length. A heavy (longer) 5.56 may be too long for a .223 chamber.
I have never seen a documented case of a 5.56 causing harm in a.223 chamber.
Last edited:
Double Vision
Member
FWIW the Springfield Armory web site lists the M1A as 7.62x51mm NATO (.308 WIN).
I've fired both calibers in my M1A without an issue.
I've fired both calibers in my M1A without an issue.
jonnyc
Member
In the case of the M1A, it is a matter of primer, and not the cartridge itself. M1As have an inertial firing pin and commercial primers (read .308) can be more sensitive than military primers (read 7.62).
But to reiterate........7.62x51 and .308 are the same round.
But to reiterate........7.62x51 and .308 are the same round.
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