4000 fps in a 7mm STW w/140 Bullet?

Discussion in 'Reloading' started by gilmillan1, Mar 6, 2013.

  1. gilmillan1

    gilmillan1 Well-Known Member

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    Hello,

    I recently began shooting long range, and I took my gun to a gunsmith to get a muzzle brake on it. The guy immediately started bragging about his custom made long range rifles. I told him that i would be interested in one in the future.

    He then started to say that his guns can reach 4000 fps in a 7mm STW with a 140 grain bullet. Is this possible or is he full of it? he says that his loads are "not in the books."

    Thank you
     
  2. MTBULLET

    MTBULLET Well-Known Member

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    1. ask to watch him shoot it over YOUR chrono.
    2. run
     

  3. Trickymissfit

    Trickymissfit Well-Known Member

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    I suspect that 3500fps with a 140 grain bullet is doable, but 4,000fps? Maybe he's putting a wad of C4 between the powder and the primer! Otherwise he must be shooting at 80,000psi!!
    gary
     
  4. dirtball

    dirtball Well-Known Member

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  5. gilmillan1

    gilmillan1 Well-Known Member

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    This guys is self proclaimed the best at what he does. I told him that I wanted to shoot my 270 win to a max of 500-550 yards on deer size game, and he told me that I was nuts for even trying that. He said that the gun was only suitable for 300 yards max.
     
  6. metalhead

    metalhead Well-Known Member

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    Jack O'connor just rolled over in his grave! The 270 is capable of taking large game at that range and more. Mr. O'connor proved it many times over his 30 year career, and he did it before quality powder and bullets were available.

    I have never fired a 7stw but you'd be hard pressed to find any rifle that will shoot 4000fps safely and accurately larger than a .224.

    I'd consider finding a new smith, this one sounds a little off the charts.
     
  7. Trickymissfit

    Trickymissfit Well-Known Member

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    a .257 WBY mag with a 75 grain bullet will do an honest 3900 fps at 55K psi chamber pressure. The 6Vias will do 4100 fps with a 70 grain bullet at an unknown chamber pressure (probably about 60K psi). A .300 WBY will do 3800fps with a 110 grain bullet (bet that's wild!)
    gary
     
  8. g0rd0

    g0rd0 Well-Known Member

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    stranger things have happened. But, I too would love to see him load up one of his rifles and fire that 140 grn over a chrono at 4000fps. Mind you I would be standing back at a safe distance with my first aid kit.
    Now that I publicly put this in writeing I hope that no one gets hurt doing it.
     
  9. BrentM

    BrentM Well-Known Member

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    Find a new smith. I personally find guys like that to be untrustworthy and everything they do is questionable. The best smiths I have ever been around keep their mouth shut, their ears open, and never bag on a guy but rather gently educate him. Most good smiths let word of mouth run their business, not running of the mouth.
     
  10. CB11WYO

    CB11WYO Well-Known Member

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    I will second that one. Untrustworthy.
     
  11. sdeviation

    sdeviation Well-Known Member

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    i got there with a 100grn cup-core bullet with slippery stuff in the barrel and on the bullet ...
    yes it was hot !! in a 26 inch pipe
    now i shoot 180 bergers in it and am much more happy... lol
     
  12. Garycrow

    Garycrow Well-Known Member

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    He's full of crap, you'd have to be running extreme pressures to get that out of a 7mm stw with a 140 gr bullet.

    I had a 7mm stw with a 27" hart barrel. The fastest I ever chrono'd a 140 gr bullet out of it was 3610 and it gave a very hard bolt lift and a flattened primer which basically fell out of the case. I never tried that load again and backed down several grains after that experience. My hunting loads I ran a 140 gr partition at 3450 and considered that as max.

    Anybody that claims 4000 fps with a 140 gr bullet out of a 7mm stw at any man-portable barrel length is a lying POS, a fool, or both.
     
  13. Lefty7mmstw

    Lefty7mmstw Well-Known Member

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    I've seen 7stw's do an honest 3500 fps with a 140, and that was about it with slow burning powders. I was running my sendero with rl25 before data came out using the 140 accubond at 3500 fps. I was also doing load work-ups with my father's 7stw and hit 3500 fps with it using aa8700 and a mild overload. The caliber is really only good for 3400-3450 fps with a 140. That's plenty fast though.

    The fastest I've ever pushed a 7mm was the 120 sierra in a 7rum with AA8700 under the hood. I was getting an honest 4000 fps with book loads. I was looking at a deer vaporizing load for it, but the rifle had a bad chamber and never shot well at all so it went to rifle heaven.
     
  14. Trickymissfit

    Trickymissfit Well-Known Member

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    another major problem with driving most of the 7mm bullets that fast is that they'll probably explode after a couple inches of impact on something like a deer. Just not made for those kind of velocities
    gary