300 RUM Case shortening

Discussion in 'Reloading' started by coupalr, Oct 20, 2006.

  1. coupalr

    coupalr Well-Known Member

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    How hard would it be to shorten the 300RUM case .250"? I am thinking of rechambering a 300 win mag to a shortened version of the 300RUM if forming the case would not be to difficult. I want more power than the 300 win mag but less than the 300RUM. I know the Dakota fits in there but the brass availability is my concern. Does anyone here load their 300 RUM down. If so what powder are you using and what is the load density like.
     
  2. abinok

    abinok Writers Guild

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    Id look at the 338RUM first and see if it fits the bill. AIf that won't do what you want, pick your favorite die mfg, and talk to them about a forming die.

    One other option would be the various 30 caliber cartridges on the full length 375H&H case. 300Wby, 30-8mmremmag, 308 Bear, 300Ackley and all the likes of those.
     

  3. biff's reloading

    biff's reloading Well-Known Member

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    if u dont mind telling.... how come u dont want the 300rum? wouldnt that just be the easiest?
     
  4. coupalr

    coupalr Well-Known Member

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    I just don't think you are getting enough of a gain shooting 20gn more powder in the 300 RUM over the 300wm. I just think that a RUM case that is shortened to hold the same amount of powder as the 300wm would be more efficient. It would be like the 300wsm but improved.
     
  5. royinidaho

    royinidaho Writers Guild

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    I recently resized 7mmRUM to 338RUM. Necks did good. Shoulders didn't. Dimpled every one of them. Still noticeable after shooting but they shoot ok.

    Annealing didn't help.....
     
  6. Hired Gun

    Hired Gun Well-Known Member

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    [ QUOTE ]
    I just don't think you are getting enough of a gain shooting 20gn more powder in the 300 RUM over the 300wm. I just think that a RUM case that is shortened to hold the same amount of powder as the 300wm would be more efficient. It would be like the 300wsm but improved.

    [/ QUOTE ]

    The gain in speed in any sport at the upper ends is never linear. Doesn't seem right a 200 horse boat will run 65 mph and the same hull need over 600 horses to go 100 mph. (not exact figures)

    What is 20 grains? 25 less loads out of a can of powder. I can afford that.

    I have found the most efficient means of picking up performance is to just put a longer barrel on it.

    A 300Wby sounds like exactly what you are looking for. Mine will do 200 grain Accubonds at 3100 comfortably with only 83 grains of IMR-7828SSC in a 26" barrel.
     
  7. Bug

    Bug Active Member

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    Fwiw,
    The idea, as you presented it, would be very simple to accomplish. One could simply cut .250" off the bottom of the sizing & seater dies. After resizing, trim the extra-long case neck back to original length. It will most likely require turning case necks - they'll be too thick. Then make up a dummy round. Have your 'smith chamber your rifle using your dummy round as a "Go" headspace guage. Should he go a smidge too deep, you can always back off on the die. You will probably have to do a little work on the feed rails, as the UM case is considerably wider. It won't be any sort of a big chore,though. If it's really what you want, then go for it. You'll likely have the only one around. /ubbthreads/images/graemlins/grin.gif
     
  8. 300Rummy

    300Rummy Active Member

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    Buy a 300 Weatherby[ QUOTE ]
    How hard would it be to shorten the 300RUM case .250"? I am thinking of rechambering a 300 win mag to a shortened version of the 300RUM if forming the case would not be to difficult. I want more power than the 300 win mag but less than the 300RUM. I know the Dakota fits in there but the brass availability is my concern. Does anyone here load their 300 RUM down. If so what powder are you using and what is the load density like.

    [/ QUOTE ]