Page 1 of 2 12 LastLast
Results 1 to 10 of 16

Thread: .308 Winchester vs. 7.62x51 mm pressure

  1. #1
    Join Date
    Dec 2006
    Location
    Commonwealth of Virginia
    Posts
    3,749
    Feedback Score
    2 (100%)

    .308 Winchester vs. 7.62x51 mm pressure

    I was talking to a friend today and he found some information on the errornet that stated that the commercial .308 Win ammo is loaded to higher pressures than military 7.62 x 51 mm (NATO) ammo.

    I was always under the impression that this was the reverse as proven by the generally thicker base of the military cases. Can anyone point me to a difinitive reference on this (one way or another)? TIA.
    Last edited by CarlosDJackal; 01-01-11 at 20:30.
    We must not believe the Evil One when he tells us that there is nothing we can do in the face of violence, injustice and sin. - Pope Francis I

  2. #2
    Join Date
    Dec 2008
    Location
    Ohio
    Posts
    763
    Feedback Score
    5 (100%)
    I had heard this too before, but I can't remember where. With a quick search, I found the following website. I don't know that it could be termed 'definitive' or not, but until someone tells me this site is often erroneous I will continue to find it useful.

    http://www.6mmbr.com/308win.html

  3. #3
    Join Date
    Sep 2010
    Location
    MI
    Posts
    600
    Feedback Score
    0
    7.62 NATO is lower pressure than .308 Winchester.
    I'm an FFL/gunsmith, not the holster company. We specialize in subsonic ammunition and wholesale rifles.

  4. #4
    Join Date
    Mar 2009
    Location
    Alabama
    Posts
    2,770
    Feedback Score
    0
    The SAMMI/CIP maximum pressure for the .308 Win cartridge is 62,000 psi, while the 7.62x51 max is 50,000 psi

    http://www.6mmbr.com/308win.html

    See it has already been posted by PlatoCATM
    Last edited by Thomas M-4; 01-01-11 at 23:31.

  5. #5
    Join Date
    Dec 2006
    Location
    Commonwealth of Virginia
    Posts
    3,749
    Feedback Score
    2 (100%)
    That's interesting because I remember another website that states the opposite max pressure. I'll have to keep digging.
    We must not believe the Evil One when he tells us that there is nothing we can do in the face of violence, injustice and sin. - Pope Francis I

  6. #6
    Join Date
    Jun 2010
    Location
    oh
    Posts
    144
    Feedback Score
    0
    .308 is higher pressure than 7.62N. I dont have the link to back it up but ive looked it up before.

    SAAMI and MIL pressures are measured in different places IIRC so thats why you may see some literature list 7.62N as higher pressure.
    I have no ambition in this world but one, and that is to be a fireman. The position may, in the eyes of some, appear to be a lowly one; but we who know the work which the fireman has to do believe that his is a noble calling. Our proudest moment is to save lives. ~Edward F. Croker

  7. #7
    Join Date
    Aug 2007
    Posts
    786
    Feedback Score
    0
    7.62 NATO and 308 Win have about the same maximun chamber pressure. You cannot directly compare the way CIP measures pressure to SAAMI to NATO, so the often cited differences are apples to oranges. I have written to many ammunition companies and even makers of pressure testing equipment to confirm this.

    You do have to be careful about the pressure curve, the 7.62 N normally uses relatively fast powders and the gas port pressure so the gas port pressure is kept at bay. Some 308 can be loaded with slow powders (specially the "light magnum" kind of loads), and thus the port pressure can be vastly different with functional/durability problems in some guns.

  8. #8
    Join Date
    Jun 2009
    Posts
    1,871
    Feedback Score
    0
    They could be confusing the 308/7.62 with 5.56 and 223. 308 is higher than 7.62 and 5.56 is higher than 223.

  9. #9
    Join Date
    Feb 2008
    Location
    Anna, TX
    Posts
    6,315
    Feedback Score
    26 (100%)
    My understanding has always been that 7.62 was lower pressure than .308. Generally speaking, he thicker case on 7.62 means less powder.

    This is somewhat counterintuitive since 5.56 is generally a higher pressure than .223.

    This should not be construed as saying that .308 is "better" than 7.62. Especially if you reload the .308 brass might be considered to be more likely to rupture or do other bad things.

    I think TiroFijo is pretty spot on.
    Last edited by Gutshot John; 01-02-11 at 19:43.
    It is bad policy to fear the resentment of an enemy. -Ethan Allen

  10. #10
    Join Date
    Dec 2009
    Location
    NM
    Posts
    1,476
    Feedback Score
    0
    Quote Originally Posted by CarlosDJackal View Post
    I was talking to a friend today and he found some information on the errornet ...
    Should have stopped him right there. It's an Internet Rumor that just won't die.

    You cannot compare the military measurement, which is 52,000 PSI with the copper crusher gauge to the SAAMI 62,000 PSI which is a piezoelectric transducer gauge measurement.

    Military measurements in CUPs VS SAAMI in (piezo) using other calibers such as the 30-06 show about the same spread.

    In reality, Max pressure for .308 and 7.62x51 are about the same.

    DIE RUMOR DIE!

Page 1 of 2 12 LastLast

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •