338 rum (improved???)

Discussion in 'Long Range Hunting & Shooting' started by 600BP, Dec 9, 2010.

  1. 600BP

    600BP Well-Known Member

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    A quick question for those in the know. I have a 338 RUM that I would like to have re-built. Possibly just having a 30 inch barrel put on, or changing to a 338 Edge (or Edge +P:D). My question is: has anyone tried to change the shoulder on the original 338 RUM to get better ballistics (338 RUM Improved?). If so, was it a successful or didn't it give any better performance than the original round. Just being curious before I have the gun re-built.lightbulb
     
    Last edited: Dec 9, 2010
  2. angus-5024

    angus-5024 Well-Known Member

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    from my understanding the .338 RUM cannot be improved very much. Niether can the edge. Not that it cant be dont, it just doesnt help much. If your gonna screw a new tube on your rifle and your thinking a 30" i would go for the EDGE. If you have a big action (WBY or custom) I would go Lapua Improved. The +P sound promising, but dont hold your breath.
     

  3. geargrinder

    geargrinder Well-Known Member

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    Search for Goodgrouper and his 338Thunder. That's basically what it is.
     
  4. 600BP

    600BP Well-Known Member

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    Thanks. I just happen to have two mark V actions sitting in the safe.
     
  5. 338 bruce

    338 bruce Well-Known Member

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    do a search for tejas, 338 tejas 300 smk 2950- 3000 fps
     
  6. B23

    B23 Well-Known Member

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    What's the H2O capacity of a 338Edge improved?
     
  7. Long Time Long Ranger

    Long Time Long Ranger Well-Known Member

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    You just can't gain enough powder capacity with improving the ultramag case to make it worthwhile. With 338 it takes quite a bit of powder to make a noticable difference. That is why the 338 RUM, 338-300 RUM or edge or whatever, and 338 lapua all shoot exactly the same. The difference between barrels in either one determines whether your accuracy load will be in the 2700's or 2800's fps with the 300 smk and not which of these three you choose. The lapua case has more room for improvement and you can gain some there and jump into the 2900's fps with the 300 grain. Then the huge 378 wby case improved and the 416 rigby imp case can get you over 3100 fps. To get the extra velocities 3-5 grains more powder in an ultramag case just isn't going to matter. 15-20 more grains in the big cases will give you a little extra velocity. The Excalibur which is about the same thing as a 416 rigby improved is about the best you can do with easy to get brass for your mk 5 action. They can get over 3100 fps with the 300 smk in a 30 inch barrel. It is a standard cartridge which makes it much easier.
     
  8. meatyrem

    meatyrem Well-Known Member

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    338-300RUM? What is this. How is it different than the 338RUM? I thought the 338RUM was a necked up 300RUM.
     
  9. Long Time Long Ranger

    Long Time Long Ranger Well-Known Member

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    338-300 RUM is just that. A 300 RUM necked to 338. It is what we wildcatted from 1998-2001 until the 338 RUM came out. They shortenned the 338 RUM case slightly so it would feed better in the 700 actions with the bullets seated properly. Changes the capacity slightly but performance is the same.
     
  10. geargrinder

    geargrinder Well-Known Member

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    Like LTLR said, they are different.

    The 338-300RUM is also called the 338Edge or 338Catbird. Mostly around here, by Edge.
     
  11. meatyrem

    meatyrem Well-Known Member

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    Oh, that clears up a lot for me. I was also thimking the edge was something totally different too. I was really close at one point on getting the 338RUM but decided that "what can I not do with one of my 300RUMs that I need a 338 for".:) I guess the only reason I would really concider getting a 338RUM is if I lived where the elk and moose roamed with an occasional grizz. But just for added insurance tho. But I will never feel under gunned with my 300RUM.:)
     
  12. Long Time Long Ranger

    Long Time Long Ranger Well-Known Member

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    If you have a 300 RUM you can kill stuff as far as you can hit it. No need for the 338 unless you just want one. You are fine with what you have.
     
  13. 600BP

    600BP Well-Known Member

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    338 Excalibur....the A Square right? I haven't heard or read anything about this round recently. Truthfully I don't even know anyone who has any working knowledge of this round. Is it as accurate at the majority of the 33's or not so much. I don't mind burning the powder as long as the results are what I hope for. Anybody?
     
  14. 338 bruce

    338 bruce Well-Known Member

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    The 338 rum will push a 300 smk at 2750 fps, the edge 2850 fps the tejas 2950 fps with everything else the same.