Gunsmithing  .408 RUM project

.416 Crucial

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Aug 11, 2011
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I have a .300 rum that I was going to build a .338 edge from and got to thinking about necking up a .375 or .300 rum to accept some solid match bullets intended for a .408 cheytac. I don't know if it would push the 408gr vlds fast enough but I would sure like to know if I have the makings of a 1500-2000 yd hammer before I call a reamer company. So any ideas or have I totally lost it?
 

GasLight

That Guy
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Re: .408 RUM project

I think with the bullets available for the .375, and what is 'potentially' in the pipeline, it might make more sense to go straight .375 RUM. What would you gain by going .408 over the .375?

Just speaking .375 RUM vs .408 RUM:

Die cost WIN .375
High BC Bullets WIN .375
Performance WIN .375
 

Strangedays

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  • Feb 27, 2009
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    Re: .408 RUM project

    Sometimes its not the best to be the only guy with a toy that everyone else does not want. Just saying. Make life easier and go with anything else than that
    smile.gif
     

    .416 Crucial

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    Aug 11, 2011
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    Re: .408 RUM project

    Thanks gaslight. Those 408gr .375 vlds forget who makes them claim over a 1.0 bc. Guess the reamer would just need a long throat and a hell of a twist barrel.
     

    .416 Crucial

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    Aug 11, 2011
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    Re: .408 RUM project

    If one could come up with a case that wouldn't need much modification and would produce the same velocity ( or close) as the cheytac without the cost and availability issues I believe you would have something. Wind drift and energy to name two pros.
     

    krlemas

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    Dec 9, 2007
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    Re: .408 RUM project

    How about 378 Wby,378 Wby.Ack.Imp, 375/338Lapua Imp. or 375/416 Rigby Improved??
     

    GasLight

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    Re: .408 RUM project

    The Cheytac case is tough to beat at a better price, you will get all of 2000-2500 capability out of a .375 Ultra Mag though, and not have near the expense in terms of action, brass, reloading dies. Once you get capable with the 375 RUM, you will know what you want/need in a faster caliber is my guess
     

    Magnumslice

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    Jan 8, 2012
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    Re: .408 RUM project

    i plan on getting a 375 cheytac put together . as i have faith in this caliber and think it will catch on and brass will become more available. somtimes a lapua isnt enough
    smile.gif
     

    paul2atlo8

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    Jan 31, 2007
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    Re: .408 RUM project

    For what its worth,have shot the .375ultra mag with the high BC bullet mentioned earlier (lost river) its a lath turned solid at 350grns it shot good, half moa out of a 1:10 twist.Just could not get the velocity past 2620fps.out of a 26" barrel.
     

    JWV

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    Dec 18, 2009
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    Re: .408 RUM project

    I have a buddy with a 375 RUM (factory Remington Alaskan model) and he is having it re-barreled to a kreiger with a long throat. Should be pretty awesome and the ballistics are still great with the rum case.
     

    .416 Crucial

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    Aug 11, 2011
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    Re: .408 RUM project

    It doesn't look like I'm goin to get the speed out of any case that will cycle in an rum sized action. To bad there is not a surplus of rigby actions on this continent. I may just go with the .375 rum for now because at 2500 yds whatever difference there is in dope between the calibers is still going to require tons of elevation. Perhaps the lost river will be good for the wind but I don't build rifles around one type of bullet no matter how badass and tempting they are.