Powders to try for 338-378 accumark

Discussion in 'Reloading' started by DUNEZRUNNER, Jul 17, 2014.

  1. DUNEZRUNNER

    DUNEZRUNNER Active Member

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    Jun 10, 2013
    I finally got my dies to start reloading my 338-378 weatherby. What powders should I start looking for? I have a bunck of imr 4831. A pound of retumbo. I was thinking of getting some h1000 as well. I plan on shooting the berger 250gr otm.

    Thanks

    Thomas
     
  2. wby mag

    wby mag Member

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    Nov 11, 2013
    I use H1000 and RL33 in mine for 300gr bullets.
     

  3. jfseaman

    jfseaman Well-Known Member

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    I don't have a 338-378 Wby so take this with a grain of salt. I have used all the other powders in you inventory in big magnums so have a real world feel for them.

    If it were me, I'd start with Retumbo. Best velocity vs. load density.
    If I couldn't get that to work, H1000, then H4831

    but

    If you have a bunch of H4831 and you are not using it for some other load it would be a reasonable choice.

    Take Aim at Rifle Reloading Data | Hodgdon Reloading lists loads for all your powder choices.
     
  4. SA1000

    SA1000 Well-Known Member

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    Jan 18, 2014
    I had one that I used for hunting in Alaska and I load retumbo in it.
     
  5. speeders

    speeders Well-Known Member

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    May 25, 2005
    I loaded my buddies factory accumark with 300 gr bergers seated to just fit in the magazine over 101 gr of H1000. Shoots right at .5 MOA after a bedding job.

    Lots of info here

    http://www.weatherby.dk/forum.php
     
  6. highridge1

    highridge1 Well-Known Member

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    Jan 24, 2008
    RL33 gave me 100 fps over everything else I tried, with great accuracy and a low ES