Twist and lands design vs. barnes .270 130gr. tripple shock

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by 308 nate, Jan 30, 2007.

  1. 308 nate

    308 nate Well-Known Member

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    first off the .270 is a caliber I have not dabbled much in as I am partial to 7mm.
    I have a request to build a custom rifle in .270wsm and the customer wants to use the Barnes tripple shock. I was just wondering if anyone had found a land design that shot the barnes bullets better than another land design as I know they can be slightly finicky.
    Just thought I would ask here as this board has a wealth of knowledge.
    Also, do the Barnes tripple shock like to be spun fast?
    I was thinking a 1 in 9 twist, any recommendations?

    Thanks again,
    308nate
     
  2. travelr47

    travelr47 Active Member

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    Nate,
    I don't have any personal experience with the 270 WSM,
    but have loaded the Barnes 130 gr TSX for several 270 win
    rifles with excellent results in all rifles (M70s).
    Standard factory barrels, rate of twist, and number of
    lands/grooves.
    H-4831 & Reloader 19 have produced the most accurate groups:
    borderline MOA to -MOA.

    Been shooting the Barnes bullets for years (since the late 980s) and haven't notice any "finicky" behavior, per say.
    I started with Barnes' X-bullet, but have changed over to the TSX bullet after shooting my first box. They don't like dirty barrels, but then dirty barrels don't normally provide the best accuracy anyway. Barnes recommends seating the bullet off the rifling by .050", but I know folks who obtain
    their best accuracy by seating them off .030". Depending on
    the quality of the bore, some rifles copper foul worse than others. And this can be an issue in terms of clean-up. Maybe I've just been lucky, but I have two custom barrels (1-stainless, 1 chromoly) and neither one copper fouls as much as shooting gilded metal jacketed bullets. Barrels are chambered 7x57(120-gr TSX @ 3200 fps MV) & 280 Rem(160-gr TSX@ 2800 fps MV), rate of twist 1:10 & 1:9, respectively.
    Add one factory rifle acquired last month, and it doesn't copper foul either shooiting the TSX, and it shoots 30-cal small groups with the 168-gr TSX.

    Re rate of twist, if it was my rifle, I'd prefer the slower
    1:10 rate of twist. 1:10 will stabilize the Barnes 150-gr
    TSX without any problems, and is easier on the barrel at
    3,000-3,100 fps MV w/130-gr bullet, and has more flexibility than the 1:9 rate of twist. I've read about others 'suggesting' a 1:9 rate of twist for the 270 Win, but just don't see the need, even with longer bullets like Barnes' TSX, Swift's Sirocco, and others.

    Good Luck
    Dennis
     

  3. James Jones

    James Jones Well-Known Member

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    If the heaviest bullet hes planning to shoot is the 130 then I'd say go with a 1-10 maybe even a 1-12 but that could put you in a bind if he ever wanted to shoot anything heavier.
    As for the land and groove desgine , I've personaly become very fond of the 5R concept , I've had a couple Rock Creek and one Obermeyer barrels and then all shot great , I don't see why the Triple shock would be any differant. I have heard some guys that shoot the old X bullets in barrels that were made to shoot the Lost River ballisitcs bullets and they had good results with them , I think that they have a slightly "looser" , if thats a word bore,

    I'd get a Broughton (i know thats your preferance) with a
    1-10 and let it ride.

    One question I have to ask is why in the world does he want to shoot the TSX over some of the better bullets out their??
     
  4. 308 nate

    308 nate Well-Known Member

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    travelr47,
    Thanks for the info.
    I have also used the barnes bullets in other calibers with fair results,but they still never shot as good as the SMK's.
    The 1-10 twist is probably the barrel to go with.But if it were mine I would probably go with the 1 in 9 so I could shoot the heavier bullets.of course if it were mine I would go with a 7mm with a 1 in 8 broughton 5C /ubbthreads/images/graemlins/grin.gif.
    But this is not my build.


    Thanks again for the info, greatly appreciated.
    308nate
     
  5. 308 nate

    308 nate Well-Known Member

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    James,
    Thanks for your info. I had also thougth of using a bore design for the lost river balistics. But I'm thinking I will go with the standard bore with this one. Broughton doesn't offer a 5C in .270 that's why I was thinking of going with a Lawton cut rifle barrel, then I could pick the twist I wanted,,maybe Id'e go with a 9.5 /ubbthreads/images/graemlins/smirk.gif

    As far as why he wants to shoot the barnes 130's...I don't know,I make my recommendations but in the end the customers always right. /ubbthreads/images/graemlins/smile.gif

    again thanks for your response,
    308nate
     
  6. NYLES

    NYLES Well-Known Member

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    Mean bullet! You sure dont have to worry about what angle you hit critters at....its going all the way one end to the other. I will say you have to do your part at the bench but when you find it they shoot great!
     
  7. James Jones

    James Jones Well-Known Member

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    Nate , you kmight also check out Rock Creek barrels , theur a cut rifled barrel in the 5R pattern and they'll give you any twist you want. I've had a couple and they shot great , as well as any Lilja or Hart I ever had and they [censored] a little faster to. Just a thought.
    www.rockcreekbarrels.com
     
  8. travelr47

    travelr47 Active Member

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    Nate,
    LOL, NO, the accuracy I've obtained with the Barnes TSX, isn't as good as the SMK! My accuracy standards aren't the most stringent though. Anytime I can put 5 shots under an inch at 100 yds works for me. I'm just a ole meat hunter.

    I've shot a lot of 150-gr bullets through the 270 win, and never experienced a problem of the bullet not stabilizing,
    or accuracy opening up. Just my prejudice, but when I want to reach out and touch you, so to speak, a .284 bore is my minimum. There are a lot of dirrerent reasons that lead me to that conclusion, but long bullet bearing surface, rate of twist, and MV above 3000 fps, lead to short barrel life.
    Sort of why the 6.5x284 works and the 264 Win Mag doesn't.
    Just a thought.
    Best of luck with your project.