i think i have a 338 weatherby ultra mag!

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by splattermatic, Jul 2, 2009.

  1. splattermatic

    splattermatic Well-Known Member

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    Nov 15, 2006
    got this from my dead machinist as the last thing he built for me.
    it's a douglas ss barreled 338 rum.

    [​IMG]

    her barrel measures right about 26.25" plus a touch to the beginning of the muzzle brake. 27.5 oal.

    i used a stoney point oal gauge to measure out a 250 sierra gameking last night, finally after waiting for brass to come in, and i got the bullet just touching the mouth of the neck !
    so a bit of adding and subtracting, i came up with a jump of .330 , after seating them at 3.650" ! weatherby's have long throats too, so i called it a 338 weatherby ultra mag !


    i loaded up 5 rounds with 95 grains of rldr 25 under the 250 and shot her today...

    i don't think i need to try anything else...!!
    [​IMG]

    after the 3 shot group, i clicked over 7or 8 clicks, since i miss counted due to my friends muzzle blast ! and fired the one just out from the dot.
    my friend shot the last one..

    so i have a question since my chrono is acting up and want a reasonable answer quicker than waiting to go to the range again with his chrono...

    with the above load and measurements, what do you think my velocity is ?

    sighted in dead on at 100 yards i counted clicks and have 93 left for distance... should be good to about 1k i hope.
     
    Last edited: Jul 3, 2009
  2. AJ Peacock

    AJ Peacock Well-Known Member

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    Nice shooting.

    My Quickload doesn't have the Gameking, but your load with the 250gr SMK shows 3054fps and more than 70k psi (pretty hot).

    That's as close as I can get for you.


    If that velocity is correct, 93 clicks (23.25moa at 1/4moa clicks) will get you exactly to 1000yds at 3000' elevation.


    AJ
     
    Last edited: Jul 2, 2009

  3. splattermatic

    splattermatic Well-Known Member

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    Nov 15, 2006
    alliants web site lists it as a max load, and at 63,??? pressure.
    it was 90 today, and no hard bolt lift, no marks, no signs of high pressure ??

    so good deal. just over 3k.. oh, i'm at about 6k elevation and hunt as high as 10k, if this helps..
     
    Last edited: Jul 2, 2009