jonnyc
Member
No, .308 was simply the commercial Winchester name for the military-developed 7.62x51 cartridge. That's it. Military and commercial chambers are manufactured to different specs, not the ammunition.
7.62 NATO or .308 Winchester
- Thread starter jwc7
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It seems to me that the ammo is made slightly different and here is why. My RCBS dies full length resize 308 brass easier than NATO brass. I'm not saying it is very much but the press handle goes down a lot harder on NATO brass. I know the NATO brass is thicker. In my DPMS 7.62X51MM NATO barrel I get away with a slight space between the shell holder and the bottom of the die (.015). This setting still allows the ammo to work well and minimizes the expansion and resizing of the brass.
The other way around, Winchester developed the round for commercial use before they sold it to the military.
bergmen
Member.
My copy of SAAMI specifications lists 1.640 Max / 1.630 Min for .308 Winchester chamber headspace specifications.
I would post the page but reproduction is prohibited by copyright.
Dan
wristtwister
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The slightly longer case length of the 7.62 X 51 is not a problem in the .308 rifles, but the .308's in the NATO chambers sometimes split the cases when fired, as the brass expands to fit the chamber. It's not something that necessarily happens every time, but it does make you take time to measure and cut your cases to length on "once fired" brass. I won't venture a guess how it acts in an AR profile rifle, but in a bolt gun, this is pretty much the rule. Once you fire a .308 in a NATO chambered rifle, you need to both do case trimming and measuring your cases before and after reloading.
I've shot a ton of both in my .308 bolt guns, and had no problems. I have, however, learned that I have to really do a good job of cleaning out the primer pockets and making sure the neck sizing is correct on the NATO rounds. They have a "military crimp" that has to be removed when sizing, and if you're properly seating your bullets, you have to make sure your cases have been properly cut. If I remember correctly the cases are about .13" different, which accounts for the case expansion of the .308's.
Sorry, but I don't have my reloading book nearby, or I'd give you exact numbers, but it isn't hard to do the math... and suffice it to say the longer cartridge throat measurement is what drives this argument (the NATO cartridge throat).
WT
I've shot a ton of both in my .308 bolt guns, and had no problems. I have, however, learned that I have to really do a good job of cleaning out the primer pockets and making sure the neck sizing is correct on the NATO rounds. They have a "military crimp" that has to be removed when sizing, and if you're properly seating your bullets, you have to make sure your cases have been properly cut. If I remember correctly the cases are about .13" different, which accounts for the case expansion of the .308's.
Sorry, but I don't have my reloading book nearby, or I'd give you exact numbers, but it isn't hard to do the math... and suffice it to say the longer cartridge throat measurement is what drives this argument (the NATO cartridge throat).
WT
NWCP
Member
Get your rifle chambered in .308 and don't worry about it.
Carl N. Brown
Member
My son has a .308 Win caliber Savage Tactical, a 7.62x51 FAL on a Imbel receiver and what turned out to be a 7.62x51 HK built on a Hesse receiver (I thought it was a CETME but I was wrong.). Over the years I have heard all the stories about how compatible/NOT the two cartridges are supposed to be. I am not sure what to believe.
The case of both 7.62x51mm NATO and .308 Winchester is rimless, bottleneck, center fire.
The .308 Win was developed from the .300 Savage which was designed to duplicate .30-06 ballistics within the action length of the Savage 1899 leveraction rifle.
The 7.62x51mm NATO was developed from the .308 Win.
I think Overall length has more to do with bullet selection than
any characteristic of the cartridge.
I suspect the case capacity of the 7.62x51mm is less as military
brass tends to be more robust since military guns are rougher on
ammo than civilian actions.
A previous thread on the subject: http://www.thehighroad.org/archive/index.php/t-318489.html&&
Sourced to QuickLoad:
.308 Win (Commercial) 56.00 grains of water,
7.62x51mm NATO (Military) 52.00 grains of water
One poster measured his 7.62x51mm from Lake City arsenal as between 54.5gr and 55.0gr of H2O.
I gather the rule should be don't mix brass from different makers or
even different lots from the same maker. Don't expect to get
consistent results if you use the same load in mixed brass.
The case of both 7.62x51mm NATO and .308 Winchester is rimless, bottleneck, center fire.
The .308 Win was developed from the .300 Savage which was designed to duplicate .30-06 ballistics within the action length of the Savage 1899 leveraction rifle.
The 7.62x51mm NATO was developed from the .308 Win.
Code:
Cartridge specifications posted at Wikipedia
7.62x51mm NATO .308 Winchester
Bullet diameter 7.82 mm (0.308 in) 0.308 in (7.8 mm)
Neck diameter 8.77 mm (0.345 in) 0.3433 in (8.72 mm)
Shoulder diameter 11.53 mm (0.454 in) 0.4539 in (11.53 mm)
Base diameter 11.94 mm (0.470 in) 0.4709 in (11.96 mm)
Rim diameter 12.01 mm (0.473 in) 0.4728 in (12.01 mm)
Rim thickness 1.27 mm (0.050 in) 0.0539 in (1.37 mm)
Case length 51.18 mm (2.015 in) 2.015 in (51.18 mm)
Overall length 69.85 mm (2.750 in) 2.800 in (71.12 mm)
Case capacity 56 gr H2O (3.64 cm2)
Maximum pressure 415 MPa (60,200 psi) 62,000 psi (430 MPa)
data sourced to data sourced to
Popenker RU.guns Federal Cartridge Co.any characteristic of the cartridge.
I suspect the case capacity of the 7.62x51mm is less as military
brass tends to be more robust since military guns are rougher on
ammo than civilian actions.
A previous thread on the subject: http://www.thehighroad.org/archive/index.php/t-318489.html&&
Sourced to QuickLoad:
.308 Win (Commercial) 56.00 grains of water,
7.62x51mm NATO (Military) 52.00 grains of water
One poster measured his 7.62x51mm from Lake City arsenal as between 54.5gr and 55.0gr of H2O.
I gather the rule should be don't mix brass from different makers or
even different lots from the same maker. Don't expect to get
consistent results if you use the same load in mixed brass.
ExAgoradzo
Member
+1 @JWC7 that's my takeaway from this discussion too! I did really appreciate the education though guys!
Since this has been asked and answered and the OP is happy we are going to end on a high note. Thanks to all the members that aided in the education of a new member.
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