Short barreled stw

Discussion in '7mm STW' started by jsthntn247, Jul 13, 2013.

  1. jsthntn247

    jsthntn247 Well-Known Member

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    A friend of mine wants me to load some 140 B-Tips in his factory Remington with 22" tube. What powder would be best to use in this barrel length. I have a 7rm with a 23" barrel and couldn't get speed with the slower powders, I feel like I might run into the same issues with the larger cased STW.
     
  2. MudRunner2005

    MudRunner2005 Well-Known Member

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    A short-barreled 7STW seems kinda pointless since it's a LR caliber, because even at 26" the STW is just barely getting a complete burn...HOWEVER, if it can be made to work it might be a cool rifle. Maybe Reloder 17 or Varget something a little faster burning might make it a cool little rifle.

    I'd tell your buddy to rebarrel it to a 26" or 28" Sendero contour barrel and use it for LR.

    Also, why is it a 22" barrel? Even the factory SPS 7mmSTW's have a 26" barrel... Did he cut it down?
     

  3. Lefty7mmstw

    Lefty7mmstw Well-Known Member

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    With a 22" bbl you will notice some loss in speed in a 7stw but you will at least make 7 rem speed and possibly a bit more. I've got a 24" tube on my stw and I'm still able to get 175's to 3100 fps. Mudrunner is correct that the 26" pipe (or longer) is preferred but I'd shoot the barrel dead if the accuracy is there and not worry so much.
    This is the pressure trace from the 150 grain winchester factory load in my sendero 7stw. Notice the slight pressure bump at 1.2 milliseconds. That is a slight tight spot in the bore at about 16". You are already down to 30 Kpsi there and falling rather fast.
    [​IMG]
     
  4. jsthntn247

    jsthntn247 Well-Known Member

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    It's not my gun, when I saw how short the barrel was, I said wtf, that's kinda pointless. The gun is straight from the factory, hasn't been cut or modified at all. What kind of loads with rl 17 and varget and the 140's, I also thought h-4350 would be about right.
     
  5. Lefty7mmstw

    Lefty7mmstw Well-Known Member

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    I'd simply run rl22 in the 75-77 grain range with the nosler 140 or run 81-82 grains rl25 with it. As a couple of guys here have reminded me the best speed will come out with the same ( highest velocity achieving) powder even in a shorter barrel. You can fool with the system a bit by upping pressures, using better powders, and using hotter primers, but it will still hold true.
    Shorter bbl's can be fussier accuracy wise if the muzzle pressure is up at times. The only time I'd go to a faster powder is if you can't get accuracy with the powders that fill the case.
     
  6. lloydsmale

    lloydsmale Well-Known Member

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    mine is a ported 26 inch gun so in all reality a 24inch gun. Dont let anyone fool you into thinking a 24 inch barrel makes a 7stw a loud 7mag. Mine will easily outpace my hottest 7mag loads out of a 26 inch barrel by 150-250 fps. I would have to guess a 22 inch gun would run with a 26 inch 7mag. So its not as stupid as some say. A nice lightweight 22 inch 7stw would be handy to carry could be made a couple lbs lighter then a typical 7 mag and give 7mag performance which isnt all that lame. By the way in my experience a powder that gives the best velocity in a specific caliber usually will do it whether the barrel is 20 or 30 inch. Never bought into the fast powder for short barrel, slow powder for long barrel bs. My chrongraph has proven that wront just to many times.
     
  7. coyotezapper

    coyotezapper Well-Known Member

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    My all time best load in the 7stw was 78 grs rl22 with a 140 gr ballistic silvertip. The only problem was the bullet splashed on impact. I now shoot 168 gr pills.