In order to participate in the GunBroker Member forums, you must be logged in with your GunBroker.com account. Click the sign-in button at the top right of the forums page to get connected.
Options

7.62 x 39

GeriGeri Member Posts: 2,089 ✭✭✭
edited September 2014 in Ask the Experts
A friend is building a bolt action rifle in this caliber. Wants to know what bore size to use, .322 or .308? Thanks.
· Share on FacebookShare on Twitter

Comments

  • Options
    GeriGeri Member Posts: 2,089 ✭✭✭
    edited November -1
    I've been shooting bolt guns for 50 plus years, but I'm not up to speed on AK's, SKS, Mini 30's etc. I'm considering buying some such critter, for the bad-guys in my front yard, should they show up. Also, sounds like fun out in the boonies. I know a bunch of you guys are virtual experts on such pieces. Any info., recommendations on mfg.. cal. would be appreciated. I like the looks of the Ruger Mini 30, but also hear some bad things about reliability, with it THX in advance
    · Share on FacebookShare on Twitter
  • Options
    GeriGeri Member Posts: 2,089 ✭✭✭
    edited November -1
    How does the 7.62 stack up as a hunting calibre..........(vs. 270, .308, 7mm)I purchased a few cases years ago and am looking for a ruger77 in 7.62........any other bolt action rifle recommendations I could use?
    · Share on FacebookShare on Twitter
  • Options
    KAMsalesKAMsales Member Posts: 1,672 ✭✭✭✭✭
    edited November -1
    .310
    · Share on FacebookShare on Twitter
  • Options
    beantownshootahbeantownshootah Member Posts: 12,776 ✭✭✭
    edited November -1
    quote:Originally posted by Geri
    A friend is building a bolt action rifle in this caliber. Wants to know what bore size to use, .322 or .308? Thanks.

    Given THAT choice, I think he'll want .308.

    Nominally, 7.62x39 is supposed to take a .312" caliber bullet. I think the military surplus and steel case stuff is all .312". .312 bullets aren't optimal through a .308 barrel, but empirically, they do work. FWIW, Ruger mini-30 uses a .308 barrel, and lots of people do get away with shooting the .312 ammo through .308 barrels.

    .322/8mm is probably a bit too big and I think he would see some decrease in accuracy. While you probably "could" load .322 bullets into this cartridge (to create an "8mmx39"), unless you happened to be sitting on a huge supply of them, I'm not sure why you would want to do this.

    Also, if he's going to reload, .308 bullets are more readily available, and available in a much wider variety, including in match configuration. So for hunting or serious target shooting, I think .308 is basically a no-brainer.

    It wasn't one of the choices, but if you actually could get a .310" or .312" barrel that also could be viable, especially if this gun was mostly for military type ammo. Realistically, though, .308 is the standard, and I think it would be much easier/cheaper to find a barrel here in 308.
    · Share on FacebookShare on Twitter
  • Options
    KAMsalesKAMsales Member Posts: 1,672 ✭✭✭✭✭
    edited November -1
    http://www.gmriflebarrel.com/7-62x39mm-heavy-gunsmith-edition-raw-blank-24-x-1-35-4140/
    · Share on FacebookShare on Twitter
  • Options
    Mk 19Mk 19 Member Posts: 8,170
    edited November -1
    If your buddy is building the rifle to make the most out of the cartridge then he will be reloading, if he is going to reload the best would be to use a .308 bore. If the plan is to use cheap surplus ammo he will want to use the standard .312 bore.
    · Share on FacebookShare on Twitter
  • Options
    GeriGeri Member Posts: 2,089 ✭✭✭
    edited November -1
    my mistake. I ment .311 not .322. Yes he will be reloading. Thanks.
    · Share on FacebookShare on Twitter
  • Options
    dfletcherdfletcher Member Posts: 8,162 ✭✭✭
    edited November -1
    When reloading he'll want to ensure his dies match whatever it is he chooses for bullet diameter. A .310 sizer die and .308 bullets probably won't make for best results. He should have no problem finding dies in either diameter, if he for some reason likes a certain brand he can probably do a little "mix & match". I have a CZ 527 so went with .310 (or .312, whatever the heck it is)
    · Share on FacebookShare on Twitter
  • Options
    spiritsspirits Member Posts: 363 ✭✭✭
    edited November -1
    Had a gunsmith friend build me 7.62X39mm Ruger 77II stainless with a Shilen Match Select 0.308 barrel.

    Here are a few other things to consider:

    1. You need the reamer for a 0.308X39mm not the 7.62X39mm if you intend to shoot only 0.308 bullets. Ended up not finding the 0.308X39mm reamer and had to use the 7.62X39mm reamer and this caused the case necks to get expanded more.
    2. The bolt face was for a 223 Rem and had to be opened up to 0.443 inches for the head of the 7.62X39mm. If you use a bolt intended for the 30'06 case head 0.473 inches it is a sloppy fit for the 7.62X39mm case head.
    3. The Ruger 77 II 223 Rem magazine and follower didn't function satisfactorily. Ruger sent me a 220 Swift follower with a 6mm Remington magazine box and spring (either this combination or switch 6mm <-> 220 Swift - don't remember exactly). Ruger did make some all-weathers 77II's in 7.62X39mm for Davidson Sports? in 1990's.

    With Lapua? cases this was a very accurate rifle with Nosler and Sierra 125 grain bullets and IMR 4198 powder.
    · Share on FacebookShare on Twitter
  • Options
    MobuckMobuck Member Posts: 13,793 ✭✭✭✭
    edited November -1
    A .310 sizer die and .308 bullets probably won't make for best results.
    Both my die sets came with both.
    · Share on FacebookShare on Twitter
  • Options
    tsr1965tsr1965 Member Posts: 8,682 ✭✭
    edited November -1
    If your friend wants a cartridge of this performance level to shoot 0.308" diameter bullets, without all the muss and fuss, he should consider the 300 Whisper/300 AAC BLACKOUT. It is based on the 222/223 Remington case head size...actually a 221 Fireball case, necked up.

    It will use the standard 222/223 Remington bolt face, and the 223 follower, and 0.308 diameter bullets. With a 1 in 7.5 twist, he can run anything from 110 grain bullets to the 220 grain Sierra SMK. Can even go subsonic, and with a can, all you hear is the firing pin.

    If he intends to shoot bulk cheap ammo, then the 0.312 diameter is the way to go, with the 7.62x39 reamer
    quote:A .310 sizer die and .308 bullets probably won't make for best results.
    Both my die sets came with both.

    Yes, both expander balls. However the neck sizer part of the die is still the same as for the 7.62. Using the 0.308 expander will work the brass more, and eventually lead to sooner case neck failures.


    Best

    EDIT 1

    quote:How do you figure that? If the case neck is reduced to the same diameter, expanding to .308 is LESS cold working than expanding to .311. These are only conversational measurements since the actual inside neck diameter will be less than the actual bullet diameter.


    Because when you fire it in a 7.62x39 chamber it is going to EXPAND more. That is why the 0.308x39 was mentioned in an earlier post, as to get the neck dimensions of the 0.308 bullet, loaded rounds to match up better with the chamber, for better accuracy, and efficiency.


    Also, ask the PPC guys about the longevity of the 7.62x39 brass. When fired in the proper chamber, with the proper neck dimensions, it can be out standing.

    You need to check on a few things before you go calling one misguided.

    Best
    · Share on FacebookShare on Twitter
  • Options
    MobuckMobuck Member Posts: 13,793 ✭✭✭✭
    edited November -1
    "Using the 0.308 expander will work the brass more"
    How do you figure that? If the case neck is reduced to the same diameter, expanding to .308 is LESS cold working than expanding to .311. These are only conversational measurements since the actual inside neck diameter will be less than the actual bullet diameter.
    When loading boattail .308 bullets, I usually run the cases through the sizer w/o the expander/decap stem to get even more neck tension. 7.62x39 cases are NOT long life at the best and being overly concerned about "working the brass" is slightly misguided. IMHO
    · Share on FacebookShare on Twitter
Sign In or Register to comment.