7mm-08 barrel length

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by ogre, Aug 23, 2008.

  1. ogre

    ogre Member

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    I did a search, but for some reason it doesn't like it when you type things like 7-08 or 7mm-08 or 25-06 in the search block.

    I'm pretty familiar with barrel lengths for a .308 Winchester, but not on the 7mm-08. I'm wanting to build a Savage light hunting rilfe with a barrel in the 20-24" range, in a varmint contour (muzzle dia beween .8 and .85"). This rifle would typically be used for White Tail, Mullies, Coyote/Predators, and target shooting. Eleveation will vary between sea level and 5,000ft. What barrel length is typically optimal for the 7mm-08? I'm hoping to use bullets in the 130gr

    And since I'm here, what about a similar set-up in .25-06 (barrel length)? If given the choice between the .25-06 or 7mm-08, which would you chose and why?
     
  2. Longshot38

    Longshot38 Well-Known Member

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    For the 7mm-08 a 22 inch barrel should be sufficient to get complete powder burn. I might bump it up to 24 inches for the 25-06. As for which I would choose. That is tough. I like the bullet selection of both buy what can I say, I'm a 7mm guy at heart. So the 7mm would have to get my vote.
     

  3. ogre

    ogre Member

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    You wouldn't happen to have a link or matrix regarding the velocity of a 7mm-08 at 20, 22, and 24" would you?

    Thanks!
     
  4. Longshot38

    Longshot38 Well-Known Member

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    Sorry mate no such luck. 7mm-08 is a necked down 308. 308 easily achieves complete powder burn out of 22 inch barrel thus the same should hold true to 7mm-08. As for velocity a longer barrel doesn't necessarily translate to velocity. You will only gain velocity so long as the powder behind the bullet is burning and the gas is expanding. Thus once the powder is burned it is time to get that bullet out of the barrel.
     
  5. ogre

    ogre Member

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    This I know (I've read the Tac-Ops article numerous times for starters;), I was just curious what the velocities looked like from a 7mm-08 at various barrel lengths.

    Thanks

    BTW, do you use this name on all forums? I recognize it from the SC and SAS.
     
  6. J E Custom

    J E Custom Well-Known Member

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    I have the real thing and will share my experiences and some load data.

    I started with a factory barrel (18.5 in in length).
    Tried 140gr bullets,velocity was under 2800 ft/sec.

    Had the barrel changed to 20'' and picked up around 75 ft/sec Still a little slow
    for what I wanted.

    Switched to 120gr Ballistic Tips and that did the trick.

    Velocity increased to 3010 ft/sec with 49.5 grs H-414 and deer fell where they
    were shot.

    This ended up being one of my favorite rifles.

    The barrel is a 20''#7 taper shilen select match on a model 7 action and a AI
    laminated stock.

    Best group to date .053 5 shot @ 100yrds.

    A friend of mine has one with a 22'' barrel and only gets 25 to 30 ft/sec more
    so it appears 20'' to 22'' of barrel is optimum.

    With the short action and a 20'' barrel this is a very handy (short) rifle and a
    very good running deer/hog rifle .

    I have taken game over 500yrds with it and would not be afraid to shoot targets
    to 600 yards with this combo.

    For longer distance I would increase bullet weight to the 150gr bullets.

    As for the 25/06 it would need a long action and 24'' to 26'' barrel with no
    improvement in velocity with a 120gr bullet (About The largest bullet in .257).

    J E CUSTOM
     
  7. ogre

    ogre Member

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    Wow, great info! Thanks!
     
  8. davkrat

    davkrat Well-Known Member

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    Somewhat off topic. I have a 24" barrel .308 that I am considering chopping to 20". I primarily use Varget and it looks like it is several steps faster burning than H-414. In many of the reloading manuals Varget is about the slowest powder recommended for .308. Any guestimates what sort of velocity I will lose going to 20" pushing 150 grain bullets with Varget powder?
    Thanks
     
  9. coyotezapper

    coyotezapper Well-Known Member

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    7mm-08 w/22" barrel is a perfect combo. Try Barnes 120 TTSX bullets, you can kill elk with this combo. If you want to go heavier try berger 140 VLD's they are very accurate. 25-06 is built on a long action and is a little heavier. And not as many bullet choices but is still an excellent cartridge. Wow just looked at this post and it is old, thought it was new oh well.
     
    Last edited: Jun 1, 2010
  10. Gene

    Gene Well-Known Member

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    I built a 7mm-08 using a Douglas 20" featherweight barrel on a 98 action. Never chron'ed it; only hunt deer using 140 gr. Ballistic Tips and 43 grs. Varget. For deer types, I don't think you need a longer barrel. The animal will never complain.
     
  11. J E Custom

    J E Custom Well-Known Member

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    With the larger dia. of the 308 you can use faster burning powder than in the 7/08 so I would
    recomend trying a different powder in the 308.

    With a 20'' barrel you will give up very little velocity if you pick the right powder (Something
    like 4895.4064 or 3031).

    They are a little faster burning and with a shorter barrel will make up the loss in velocity.

    J E CUSTOM
     
    Last edited: Jun 1, 2010
  12. DONTSTROKEME

    DONTSTROKEME Well-Known Member

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    I am getting 2600fps with IMR4064 and 162gr Amax out of an 18" barrel.

    Gonna try RL17 as well.....but anything longer than 16" and the 7mm-08 Rem will light your smile!!!