7 stw vs 7 ultra mag

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by remcraz, Oct 17, 2012.

  1. remcraz

    remcraz Well-Known Member

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    If you load both to max charge and use the same bullet (168 berger) which barrel would have the longer life. I am going to build one of the two and want the one with the longer barrel life. I dont shoot compatition but practise alot
    Thanks
     
  2. Lefty7mmstw

    Lefty7mmstw Well-Known Member

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    stw by 2 to 1 or more. I've had both; the 7 rum with 140 sierras and rl25(at 3500fps) went about 600 rounds before showing some accuracy loss and shallow rifling. I traded my stw this spring at 1500 rounds or so and the last group shot sighting in a scope to trade it was .4" at 100 yards with a 140 sierra. I usually ran 140 accubonds in her with rl25(at 3450 fps). It was showing some shallowing(rifling) but still shooting .5 moa or so on average.
     

  3. dbhostler

    dbhostler Well-Known Member

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    They are the same. I would choose the beltless case.
    db
     
  4. Lefty7mmstw

    Lefty7mmstw Well-Known Member

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    15 grains more powder for the same velocity is NOT the same. It's a hell of a lot more heat and scouring for virtually nothing. I like the 7rum and will probably own one again, but it will be a dedicated lr rig with extremely low round count. You can actually use your stw and still keep it shoting well. I owned my last one ten years. My current one had 200 rounds and change on it and the barrel shows no wear, even heating it bad in hot weather this year. That would have killed a 7rum. If you want a rum you can put rounds through, you have to step up to 300 rum.
     
  5. dbhostler

    dbhostler Well-Known Member

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    Yeah, that's what I did, sold my 7 and stepped up to a 30.
    db
     
  6. Lefty7mmstw

    Lefty7mmstw Well-Known Member

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    me too; I use the stw in 7mm and 300 rum for beltless. I'm thinking of a 7rum the local shop has for 6 bills in ss with a good barrel, but it is a righty. I don't think I'd get more performance than my lh stw though.
     
  7. dbhostler

    dbhostler Well-Known Member

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    The 7 RUM has the largest case capacity of any commercially loaded case, but their ballistics are about the same. Don't know the price of cases if you roll your own and the availability of loaded ammo if you don't.
    tc
     
  8. Trickymissfit

    Trickymissfit Well-Known Member

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    A few years back I knew about a half dozen guys that ran a reamer thru Remington barrels to build a 7STW. Of those guys only one still shoots the round. And he's well into his third barrel! The poster is correct about the ultramag eating barrels as it's even more overbore than the 7STW! The cartidge choice for me would be the 7mm WBY mag without a second thought! Better neck and shoulders than either of the others; meaning much better barrel life with simililar velocity. But on the otherhand there's still nothing wrong with the generic 7mm Remington mag, but given the choice it'd be the Weatherby everytime.
    gary
     
  9. remcraz

    remcraz Well-Known Member

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    So how many rounds do you think you can get from the 3- STW,ULTRA MAG AND THE WEATHERBY all 7mm without overheating them. 2 shots then cool before firing another one
    Thanks Guys
     
  10. dbhostler

    dbhostler Well-Known Member

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    Depends on the thickness of the bbl. Lay your hand in it, don't let it get hot.
    db
     
  11. remcraz

    remcraz Well-Known Member

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    I have the barrel its a Krieger #5
     
  12. Trickymissfit

    Trickymissfit Well-Known Member

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    It's not so much the barrel itself, as the chamber design. I doubt that the Krieger would last anylonger than anybody elses barrel being as 90% are cut from the same numbered steel. Just can't take that kind of heat.
    gary
     
  13. dbhostler

    dbhostler Well-Known Member

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    Also ambient temp, barrel flutes, moly bullets, finish of the bore. Feel the barrel, when it gets warm, give it a rest. This is why I don't like timed fire, 20 rounds, one after another. Really hard on the barrel.
    db
     
  14. 7stw

    7stw Well-Known Member

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    Call me prejudice, or call me, been there, done that. But that is a hands down 7MM STW answer. The law of deminishing returns comes into play here also. The velocity difference between the two, versus the powder to get that is quite high. That being said, the more powder you burn, so does the barrel. I have been a STW fan since it's conception, and have experienced extremely long barrel life in my own rifles . ( plural)
    I have heard of 1200-1500 rounds before burn out. In the case of the 7 RUM, I have heard of them " biting the dust" at way less then a thousand. Actually heard of one that didn't see 600.
    As another part of your equation, I would like to throw in the accuracy and shoot ability issues. I had a 7 RUM a while ago, that at best was very finicky. By the time that I got the thing to shoot, I had about 200 rounds through it. Hear comes the good part. When I finally did get it to shoot, the velocity was no better then my STW's. And to be totally honest, it wasn't as accurate as all the hype made it out to be. I believe that you can have TOO much of a hood thing. What I mean by that is, the 7 stw is about as overbore that 7mm can be and still be SHOOTABLE.
    This may give you a little to think about. But my vote goes to the STW, imagine that !!