Need load data for 340 Weatherby

Discussion in 'Reloading' started by martyj, Feb 25, 2013.

  1. martyj

    martyj Well-Known Member

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    Was wondering if you guys could help with reloading data for a Mark V weatherby in .340. It is freebore and no signs of pressure yet.
    I tried 7828 and MRP (Mrp didnt appear to work to well)
    87.2 appears to be max on 7828 before the group gets bigger.
    I also bought a box of factory ammo and wasn’t to impressed with that at all for the price.
    How ever do have 2 boxes of Speer loaded by HSM and that is good stuff. Wish I knew what their loads were.
     
  2. George LS

    George LS Well-Known Member

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    i use 90.0 7828 250gr sierra MKHP 3109 fps in a mark 10 solid bottom it has a 30 inch 1x10 twist HART. put together around 1995..hot load and hard on brass .but it shoots .i don't use it to play.it a hunting rifle.....george
     

  3. martyj

    martyj Well-Known Member

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    how do you keep the bullet from pushing back out with out a cannelure on the bullet to crimp it in.
    I ran into that with barnes and beger bullets
     
  4. wyomingblizzard

    wyomingblizzard Well-Known Member

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    In my markV 340, the most accurate load is barnes 210ttsx with 88 grn. of imr 4831. I never crimp my loads.
     
  5. Dr. Vette

    Dr. Vette Well-Known Member

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    Neck size it only, but I also wonder how many times your cases have been shot?

    I have not had any problems with Barnes or Berger, at least not with them being pushed out.
     
  6. martyj

    martyj Well-Known Member

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    They were new Norma cases and have never been sized at the time.
     
  7. Dr. Vette

    Dr. Vette Well-Known Member

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    General consensus is that you should always size cases before loading the first time. Many sources recommend full length sizing at first. I suspect that if you check them in your rifle first for fit you "might" get away with just neck sizing them if they feed through - though I've not tried it. I have tried full length sizing and then neck sizing new-to-me brass so that they matched what I'd be doing with later loadings. You could even remove the neck expander from your full length die so that the neck isn't manipulated twice in your brass prep - I do know loaders who do this.

    If you hadn't touched them at all then I'd really wonder where your neck tension was at. That alone could cause the errors you see.

    You could always look at the bullet that HSM used, measure the length to the ogive of one of their rounds, and then load your own using 7828 with the bullet seated at the same length. That's as close as you will get to matching what they do, though you still need to check various powder levels to see what is most accurate in your rifle.