7 RUM 1/12 twist

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by Limbic, Jun 8, 2010.

  1. Limbic

    Limbic Well-Known Member

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    I don't know why. My buddy (honestly a buddy and not me :D) has recently acquired a new 7RUM with a 1/12 twist barrel. He wanted me to put together some different whitetail loads so he could shoot it up. I know that is an awfully slow barrel but I've only loaded for the 7mag so I don't know how the extra powder will change things. I was thinking of using some 140 Bergers or 139SST. I wont be pushing the envelope much and will be getting the most accuracy I can out of the loads.

    Anybody have any better bullets to try with this slow twist? Also with the MV of 3200-3400 (guessing) Will I need a bonded bullet? Something that won't fall apart with such speeds.

    He probably won't shoot much more than 300 yards.

    Also if you have a pet powder I'd like to try it out. I was going to go with the H1000/Retumbo 180VLD combo but with that twist I don't think so.:rolleyes:
     
  2. Coyboy

    Coyboy Well-Known Member

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    definatly go bonded bullet/all copper.
    140 graners may-be 150 will fly.

    My 27 inch 7rum with 175 seirra MK runs them close to 3300fps so I would be expecting 3400 plus.

    Retumbo might be too slow for the lighter bullets but it's worth a try H1000 should be good.
     

  3. Limbic

    Limbic Well-Known Member

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    think vld will come apart?
     
  4. Coyboy

    Coyboy Well-Known Member

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    The target bergers are suposed to have thicker jackets they may do fine. The hunting vlds may or may not stay together but will make a mess at impact.

    The target bullets were toughened up because match shooters were ocasionally losing a bullet between themselves and 1000 yard targets. without hitting anything, running them out of cartriges smaller than the 7 rum.