Why the 338 Lapua?

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by Engineering101, Mar 10, 2013.

  1. Engineering101

    Engineering101 Well-Known Member

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    I’ve seen quite a few folks buying 338 Lapuas. I always wonder why when the 338 Edge or even a plain vanilla RUM seem to stack up better. The volume of the cases (per QuickLoad) in grains of water are:

    108gr - 338 Lapua
    110gr - 338 RUM
    113gr - 338 Edge

    Also, the bolt face is bigger on the Lapua which puts more force on the bolt at the same chamber pressure. Overall cartridge length for the Lapua is 3.681” per SAAMI standards versus 3.600 for the others so magazines and actions have to be slightly longer.

    Lapua brass is hands down better than Remington brass, but that isn’t an issue since Nosler came out with brass for the RUMs as it is excellent.

    Also Nosler says in their latest handbook, “The 338 RUM delivers surprising accuracy for a large magnum cartridge. It has become the standard 338 caliber test round for the Nosler Ballistics Lab.” They could have picked a lot of others including the Lapua as their standard – but didn’t.

    The highest velocity that each can drive a 250 Accubond in equal length barrels is 2,941 fps for the Lapua and 2,990 fps for the 338 RUM. (Nosler reloading guide number 7.)

    From what I can see the 338 Lapua has only disadvantages compared to the 338 RUM let alone the Edge so what gives? The disadvantages are not large but still, why do they sell? Savage for example doesn’t offer a 338 RUM but they build more than one Lapua model. What am I missing?
     
  2. jcoop

    jcoop Well-Known Member

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    Well, I had a edge and while I liked it I got tired of brass issues (short life compaired to the lapua) so I sold it and built a Lapua. Nosler brass was just ok but Lapua brass is much better in my openion. SAAMI specs are for COAL and do not really mean much as the case length on the Lapua is shorter and easyer to to load in a mag and retain case capasity at the same COAL as the rum-edge. If the action used is a purpose built action than the bolt thrust is not really an issue. If you re building on a remington then the RUM and Edge obviously get the nod. I prefer the lapua only because of brass and the abilty to improve the case and gain performance. Now with Shawns brass the edge has an even more valid argument.
     

  3. Young-Gun

    Young-Gun Well-Known Member

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    I second the brass issues, Lapua Brass is second to non. the consistency between cases is in credible and if you research all the things Lapua does to make there brass the best Like neck thickness, drilled flash holes for the primer you will answer your question your self. and velocity isn't the key with Long to extreme range consistency is. So when you press a bullet into a lapua case and check run out and get less than a half of a thousandth your are a believer.
     
  4. Engineering101

    Engineering101 Well-Known Member

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    What you both said makes perfect sense. I knew there had to be something going on that wasn’t obvious and that guys that shoot Lapuas would know. Thanks for the explanation.
     
  5. MontanaRifleman

    MontanaRifleman Well-Known Member

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    AmmoGuide is showing

    338 LM, 111.8
    338 RUM, 104.8
    300 RUM (EDGE), 107.2
     
  6. Engineering101

    Engineering101 Well-Known Member

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    MontanaRifleman

    There must be some apples and oranges going on here because I’ve measured my 338 RUM case volume at 110.7 grains H2O and my 300 RUM at 116 grains H2O.
     
  7. MontanaRifleman

    MontanaRifleman Well-Known Member

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    Interesting, is that before or after firing?
     
  8. Engineering101

    Engineering101 Well-Known Member

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    MontanaRifleman

    These volumes are for fireformed brass. You need this info for QuickLoad to get the most accurate results as I believe it uses minimum dimensions by default otherwise (which is what I listed above).
     
  9. sp6x6

    sp6x6 Well-Known Member

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    Wiki showed 114 -lapua,113-rum,and I have seen 110 posted on edge.My 338 Norma holds 108 h20 and is clearly shorter than lapua.I shoot 2725-50 with 87.5 retumbo and am on 7 reloads.They all split hairs with barrel length and how much you want to push your brass.The lapua is also adopted in about 20 countries.
     
  10. Nimrodmar10

    Nimrodmar10 Well-Known Member

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    I bought my just because I like saying the word "LAPUA" :)
     
  11. TheFishBox

    TheFishBox Well-Known Member

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    Same here LAPUA it has a nice ring to it
     
  12. MontanaRifleman

    MontanaRifleman Well-Known Member

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    Midway got 338 Lapau in yesterday
     
  13. 7mmSendaro

    7mmSendaro Well-Known Member

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    I would add that the new Betram brass Shawn Carlock has for the 338 Edge is a game changer as well. Brass is no longer an issue with the Edge!
     
  14. Broz

    Broz Well-Known Member

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    I have am a Lapua and Edge fan both. I have used both and until Shawn"s brass the Lapua had the EDGE. No pun intended with brass life for sure. I have some of the new edge brass on the way and will be setting up a new edge next week for a friend. I agree this is going to level the playing field and look forward to results.

    Jeff