338 LM improved, 338/300 RUM, 338/416

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by lazylabs, Jan 19, 2007.

  1. lazylabs

    lazylabs Well-Known Member

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    I don't see much posted on the LM or the improved version and was just curious why. It seems like a large case from a great manufacturer but has very little following. I realize the boltface size difference and action cost but what are the other reasons? I have a 338/378 but would like something away from the weatherby case and a little higher quality gun than I currently have. I am holding off on the 408 case for now until we find out if sierra is going to go with the 375 bullet or not. I will be buying a custom action for any of these rounds and brass cost isn't an issue. If your spending 3K on a components, scope and rings what's another 200 for brass. I like the RUM for effiency but a little more speed would be nice. I am looking for a little experience with these rounds. Thanks
     
  2. uncleB

    uncleB Well-Known Member

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    lazylabs,
    You have asked a very touchy question.they are all awesome cartridges with similar capabitily. the 338LMI has the best brass, but the other's are very capable as well. it is hard to go wrong with a 338
     

  3. AJ Peacock

    AJ Peacock Well-Known Member

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    Lazylabs,

    One year ago, I was debating the same question. I finally decided that with a custom gun, all the components where the same regardless of the exact cartridge, except for the 408 based 338 Allen Magnum, which needs a larger receiver.

    I was close to purchasing a 338LM, 338RUM or 30RUM, and felt it would perform fine on Big elk sized game up to 1000+ yards. I already had a very accurate 7mmRM that I felt comfortable with up to 800yds or so. But after much thought I decided I should make a bigger step than a RUM or LM. Looking at the ballistics, I decided the 338AM was my particular ticket. It only took a year to decide to have Kirby (FiftyDriver) build me one of his 408 based 338s. Now I'll be waiting for one, if I had decided a year earlier, I'd already be shooting it.

    Good Luck,
    Don
     
  4. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    Of the three I would probably lean toward the 338 Edge(338-300 RUM) just because its so damn easy to load for and very high performing.

    Second would would be a toss up between the 338 Lapua Improved and the 338 Kahn(338-378 Wby with 35 degree conventional shoulder angle).

    I would not consider the 338-416 simply because with the availablility of the 338-378 Wby it is basically obsolete as the big wby will match it fps for fps and no neck forming is needed in any way.

    Again, of the three, I would probably go with a 338 Edge over the other two.

    Kirby Allen(50)
     
  5. lazylabs

    lazylabs Well-Known Member

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    I would really like to stay below the 408 capacity for a 338 right now. I will be using a custom action, cut barrel and A5L stock probably with a barrel block. I really like the LM case and the cost difference over the UM is negligable once all the parts are set. I have considered getting the lawton 8000 action with two bolts to have the LM and 408 in a switch barrel situation. I would like to pick a non-408 338 to start up now.
     
  6. Cruizin

    Cruizin Well-Known Member

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    What about a 338 edge with an improved shoulder? Anybody do any of these?
     
  7. lazylabs

    lazylabs Well-Known Member

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    I don't believe you would gain much with a sharper shoulder on the RUM case. It's already a 30 deg shoulder with minimal body taper. I don't think there is much room there to gain. The LM has a little more room to grow from what I can see. It's sad the LM case isn't .100 or 2 longer. It's just a big step from those cases to the 408...dang it. Does anyone have the case capacity numbers for the edge, LM, 338/408 and the 338/408 improved?
     
  8. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    Only thing you would really gain is the need to fireform brass. Improvements in performance would be pretty small to be honest.

    Kirby Allen(50)
     
  9. Northman

    Northman Well-Known Member

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    fifty: with just a neck down of the 408, without the fireforming, how much do you loose compared to your 338 AM?
     
  10. Cruizin

    Cruizin Well-Known Member

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    My smith was talking about this round he made with a 338/300 and a 50° shoulder. It's going to be a single shot so I was considering it. Just wondering if anyone has heard of this and if there are any case separation issues. It gives less bolt thrust, brass lasts longer, no trimming, but more expensive dies. Is it worth it?
     
  11. davewilson

    davewilson Well-Known Member

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    I'd like to hear the explanation of less bolt thrust.i have a 338/300 and i just don't think improving the case is worth a hill of beans in the long run.with the right chamber you can push the necks out and load,no fireforming.i'm still going through the first 100 pcs of unfired brass and have shot nothing less than great accuracy. i doubt an improved version will even get another 100 fps and even if you do it's only good for braggin rights at lunch break. it won't give you any advantage over a straight 338/300 to kill at long range.
     
  12. newberry

    newberry Member

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    Need some help finding Arco in ID for 408 chey tec brass need link e-mail tel# etc
     
  13. Jim Oliver

    Jim Oliver Well-Known Member

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    Probably a dumb question--but here goes;

    How are these rounds better than the standard .338 RUM?

    Thanks,
    Jim
     
  14. lazylabs

    lazylabs Well-Known Member

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    Better is a matter of opinion they can all be more accurate than the shooter. It's really just speed and figuring out how much you want to trade for the next 100 fps. That's my theory anyway. It's nice to have a little extra power and range but will I ever shoot further than the 338 RUM will handle....probably not. It's more of having the experience of getting the gun together and shooting. Just my opinion of course.