.416 application, 300 RUM vs. .375 RUM brass?

Discussion in 'Reloading' started by nw07heavy, Apr 4, 2015.

  1. nw07heavy

    nw07heavy Member

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    I have a question for those of you with .416-300 RUM, .416-375 RUM, or .416 UltraCat experience. Looking at the SAAMI drawings for the .300 RUM and .375 RUM cartridges I see that the outside case dimensions are identical, and the 30 degree shoulder beginning at 2.3873" is the same for both cases, which would indicate that either case would be suitable for loading a .416 bullet into standard RUM cases, once the length reaches 2.4540 and the neck begins. My question is whether they would reload and function equally well. I understand the .375 RUM cases would be less trouble than the .300 RUM to neck up to .416 due to needing less size increase. Is there something I am missing in regards to this brass, possibly neck thickness? I also noticed that reloading dies come in designations of .416-300 RUM, .416-375 RUM, and .416 UltraCat (all appear to have the standard RUM dimensions) and wondering what the functional differences are between these designations, and subsequent selection of reloading dies. Thanks for any insight you can provide.
     
  2. knc1105

    knc1105 Well-Known Member

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    Well I had the same question but nothing but crickets
     
  3. MagnumManiac

    MagnumManiac Well-Known Member

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    I think it may be that the neck would get thinner on the 300RUM case.
    Going from .308” to .416” is a very big step up.
    I don’t see how the reamers would be any different, the case dimensions to the shoulder datum are the same for either.

    Cheers.
     
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  4. IdahoCTD

    IdahoCTD Well-Known Member

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    They both work but the 375RUM would be one pass over a expander ball from a 416 die where as a 300 would be at least 3 steps and the potential for split necks goes up greatly if the brass isnt annealed. Plus, as was mention, the case necks will thin out a good deal starting with 300 brass.
     
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  5. Doublezranch

    Doublezranch Well-Known Member

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    Factor in one more variable...375 RUM brass has been incredibly hard to find now for many years. Bertram makes it on a whim occasionally. I have a 375 RUM and a 375 RUM wildcat. Love to shoot them, but always have to be very cognizant of picking up my brass after I make my shot in the field.
     
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  6. CA48

    CA48 Well-Known Member

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  7. knc1105

    knc1105 Well-Known Member

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    I just bought 12 boxes at Graff & Sons $26.50 box
     
  8. knc1105

    knc1105 Well-Known Member

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    If its that hard to get I just bought another 10- boxes for a total of 22 it was $26.09 a box if you bought 10, $1.30 a round is a great price. Thanks for the heads up