Bore Diameter myths??????

Discussion in 'The Powder Keg' started by Tami, Sep 8, 2002.

  1. Tami

    Tami Guest

    What is the truth about the bore diameter on an SKS? I have heard two different things back and forth constantly. I was told years ago that the SKS had a different bore size than a .308 or 30 caliber. I know the 762x39 typically shoots bullets around .310 to .312 (I think). I was told first that the barrels were a larger bore accordingly...Now I have also heard from a few people that this isnt true....that in fact the SKS bore IS the same diameter as most other 30 caliber rifles, and one person told us that the lighter weight/larger diameter bullets are used to increase chamber pressure so that the SKS action and bolt will function reliably as a semi-automatic.
    Does anyone here know absolutely what is the truth?
    Sorry for being so long winded about it, but I dont know how to explain what I am asking in simpler words. I am not a gunsmith or anything. Please help. I am sick of all the unoficial opinions and guesses as to what is true and I dont think I could think of ANY way to actually measure it. Thank You Thank You!
  2. Tami

    Tami Guest

    One more thing I forgot......

    I asked a few weeks ago if anyone knew where I could go on the internet to view an SKS Manual, and someone posted a link for a site.....but it had either expired or was not working. Does anyone know anywhere else I can get a manual online, or could anyone send a file to me in my E-mail? Thanks

  3. stead

    stead Guest

    use your search engine type ak sks will find a link for manuals
  4. Tami,

    ALthough this site I am about to give doesn't have a manual, per se, it does have some info on specs, disassembly, etc.

    It might help until you find a manual site.

    It also has interesting info about other older mil type weapons.
    Last edited: Sep 8, 2002
  5. Calvin

    Calvin G&G Evangelist

    Tami, the bore diameters on the SKS's do vary in size from .308 to .311. They are generally in the .310 area, though.
    As far as the lighter weight/large diameter theory, it sounds like somone was at a loss when asked that question.
    The cartridge was originally designed to fire a 123-grain bullet at a nominal velocity of 2350fps. The SKS was designed around the cartridge, not the other way around. Also, the SKS was designed with loose tolerances so it would function when it was very dirty, and through a very broad temperature extreme. That's why they work as good as they do. And, it's why they aren't extremely accurate. They were made for the average combat distance of the time, which was 400 meters. And, the Russians used a "bigger is better" theory on their troop movements. The Russians would simply try to be the biggest, fastest, and most overwhelming force on the battlefield.
    As far as the manual, I would agree with Stead.
    Hope this cleared things up a little!:)
  6. BattleRifleG3

    BattleRifleG3 G&G Evangelist

    Standard bullets for the SKS are .311" I suppose .312" in't too far off to use, especially as the rifling can wear under excessive use. But I really don't think the bore is .308" on any of them. .311" seems a bit too far oversized to be safe. I for one would never load .311" bullets for a bore I knew was .308" I'm not sure, but that may be one problem with the Mini-30.
    Now using .308" bullets in a .311" bore is just fine, in fact people do it with good results.
  7. Calvin

    Calvin G&G Evangelist

    BRG3, I have a 1954 Tula SKS with a .308 diameter bore. Slugged it twice to make sure. It's more the exception, I'm sure.
    However, the Mini-Thirty has problems because of the barrel and the stock, not the bore size.
  8. BattleRifleG3

    BattleRifleG3 G&G Evangelist

    I read that the Mini 30 was designed for 308 bullets and that Ruger advised against using anything but American commercian brass cased ammo.
    That's the first SKS I ever heard of that's 308 caliber. Maybe it's only the early Russians.
  9. Tami

    Tami Guest

    Thank you Everybody, especially Calvin.....

    That sounded like a very informed reply. Thank You. It sounds like the first info I heard was correct I also found a site last night with Specifications for the Soviet SKS. It says .301 for the bore and .311 for the groove diameter. I dont know if it would be the same for the Chinese, but that seems to make sense. I feel satisfied now. Ha Ha....I was Right! Thanks everybody.
  10. Poccur

    Poccur Guest

    SKS manual

    I have the US army SKS manual as a PDF...if you still want a manual...give me a shout:)