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 What Does this mean 7.62x ??
SVT-Sinister  [Member]
9/19/2005 6:24:54 AM EST
I see there are a couple different types of .308. What does the numbers after the x mean? For example:

7.62x25
7.62x54R
7.62x39 What does the 25, 54R, and 39 mean?

Thanks
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AssaultRifler  [Team Member]
9/19/2005 6:26:27 AM EST
length of the case in millimeters

the 7.62x39 case is actually 38.70 mm in length

Forest  [Team Member]
9/19/2005 6:27:46 AM EST
Length of the case in milimeters.

The (R) at the end of the x54R indicates the round is rimmed.

7.62x51 is the NATO .30 cal round (the civilian equivalent is .308)

7.62x63 IIRC is the Euro nomenclature for .30-06
SVT-Sinister  [Member]
9/19/2005 6:36:17 AM EST
So those ammos are not compatable with each other right. I mean i cant shoot that in my ar-10 .308 right?
Forest  [Team Member]
9/19/2005 6:39:20 AM EST
Correct, they are NOT interchangable.
uglygun  [Member]
9/19/2005 10:28:12 AM EST
7.62x39mm...

Kinda like having a piece of lumber that is 2x4 or 2x8.

With ammo, bullet diameter followed by case length.
chevyrulez1  [Team Member]
9/20/2005 11:48:21 AM EST

Originally Posted By SVT-Sinister:
So those ammos are not compatable with each other right. I mean i cant shoot that in my ar-10 .308 right?



These ammunitions are not interchangeable. The 7.62 refers to the bullet diameter, and is almost always an estimation. For example, the 7.62x51 will be .308 of an inch. A 7.62x39 bullet will be .311 even though it has the same 7.62 diameter designation.
Even if they do use the same diameter, the shell casing, rim, etc. are completely different. Never fire any ammunition in a firearm unless it specifies in the owners manual that you can do so safely.
Blammer  [Member]
9/20/2005 11:52:59 AM EST
you will want the 7.62X51 for your 308 AR-10.

NONE of the above you mentioned are interchangeable

7.62x51 IS almost IDENTICAL to .308 for practical purposes it is interchangable.
there are subtle differences just as there are subtle differences between 5.56 and 223

7.62x51 is military normanclature
308 is civy words
SBR7_11  [Team Member]
9/20/2005 4:35:15 PM EST
Here, left to right -

7.62 x 25, 7.62 x 39, 7.62 x 51, 7.62 x 54R, 7.62 x 63

SVT-Sinister  [Member]
9/22/2005 7:39:37 PM EST
thanks guys. I really did learn alot about ammo just now.
SSeric02  [Team Member]
9/22/2005 8:43:17 PM EST

Originally Posted By SBR7_11:
Here, left to right -

7.62 x 25, 7.62 x 39, 7.62 x 51, 7.62 x 54R, 7.62 x 63

img.photobucket.com/albums/v504/capttoyota/7.jpg



Great comparison pic.
Daubs  [Member]
9/23/2005 12:02:27 PM EST

Originally Posted By SBR7_11:
Here, left to right -

7.62 x 25, 7.62 x 39, 7.62 x 51, 7.62 x 54R, 7.62 x 63



SBR7_11 has lots of guns

Something to note, 30-06 and 308 have the same power charge even though the 30-06 has a longer case.
SBR7_11  [Team Member]
9/23/2005 4:37:41 PM EST

Originally Posted By Daubs:

Something to note, 30-06 and 308 have the same power charge even though the 30-06 has a longer case.



EEEEEEh, 7.62x51 uses typically 5-8gr less powder than the 30-06 in std mil loads, and the 7.61x51 can do similar to the -06, until heavier bullets are used.

The only real reason I have 30-06 is initially I came into a good load of 1 fire WCC military brass for free, so the M98 lost the 8x57 barrel, and on went the 30-06... Have about a 5 gallon pail full of free 1 fire brass now, and wife cousin gives me his brass too. I have busted my fair share of deer with it.
Troy  [Site Staff]
9/25/2005 6:13:04 AM EST

Originally Posted By Daubs:
Something to note, 30-06 and 308 have the same power charge even though the 30-06 has a longer case.



False!

The difference in case volume usually means that the two are loaded with different types of powder to begin with, and the weight and/or volume of the charge used is almost always different.

What IS true is that the resulting velocity of MILITARY FMJ loads between the two rounds are nearly identical, so the MILITARY rounds have virtually identical performance.

In the civilian world, the .30-06 case is more flexible, as the larger case volume allows longer, heavier bullets (200-220gr) to be loaded, whereas the .308 doesn't have the case capacity for these bullets. This flexibility is the main reason why .30-06 remains the #1 hunting caliber in the US, even though performance with 180gr and lighter bullets is almost identical to .308.

-Troy
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