270 win vs 280 ai

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by tbrice23, Apr 30, 2014.

  1. tbrice23

    tbrice23 Well-Known Member

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    Other than having to sell all my 270 win bullets & dies and quite a bit more work converting 270 brass to 280ai CAN ANYONE CONVINCE ME to stay with 270 win on my re barrel project ??? Particularly from an accuracy standpoint. Target pics welcome.
    (Come on Royinidaho)

    Keep in mind, I have two 7mm rem mags already.
     
    Last edited: Apr 30, 2014
  2. CogburnR

    CogburnR Well-Known Member

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    Just do a 270AI or 270 Sherman.

    Velocity for the 270 Sherman is the same(or better) as the 280AI and have a higher BC bullet in the same weight. The 270 Sherman will drive the 165 Matrix 3000fps+. The 280AI has about 5% less powder capacity than a 270 Sherman. A straight 270 Win will be 150fps or so slower.

    7mm Matrix vld bc .608

    270 Matrix 165 vld .650.

    7mm 180 Berger vld bc .659

    270 Matrix 175 vld bc .680
     

  3. gohring3006

    gohring3006 Well-Known Member

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    I'm with coburnr I would do a 270ai or Sherman especially if you already have some 7s
     
  4. tbrice23

    tbrice23 Well-Known Member

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    I looked into it.
    Douglas has reamers for
    270 ai but no one has dies. I talked to Mark Penrod and he told me in 30 years gunsmithing he's never had a request for it.
    Do you know where to get the dies without 4month wait?
     
  5. CogburnR

    CogburnR Well-Known Member

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  6. MudRunner2005

    MudRunner2005 Well-Known Member

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    Redding 3-Die Set 270 Winchester Improved 40-Degree Shoulder

    You could always contact Redding to see if they happen to have a set sitting on the shelf... You just never know.
     
  7. Lefty7mmstw

    Lefty7mmstw Well-Known Member

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    Why bother going ai imo. The 270 will hold nearly 70 grains of slow burning ball powder (yep, I've got some loaded with 69.5 gr. wc872 with a 130bonded at present) and over 60gr. of stick. You'll only get a few grains more powder in it after the ai job; that's a lot of cost to be "special". Use your 7mag's or step up to the 7stw or7rum if you want that extra bit of power. If you want more out of your standard bolt face consider a 338' 06 or 35 whelen.
    The biggest gain you get when loading for the ai rounds is loading them hotter due to reduced bolt thrust. The 5% or less you get in extra case capacity will net you 2.5% or less actual speed increase.
     
  8. tbrice23

    tbrice23 Well-Known Member

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    So if I was loading to 3000 fps with 140 vld in my old 270 barrel I would only gain
    75 fps with a 270 ai?
     
    Last edited: Apr 30, 2014
  9. MudRunner2005

    MudRunner2005 Well-Known Member

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    When you AI, you are supposed to gain around 150 fps.
     
  10. davkrat

    davkrat Well-Known Member

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    I think you would gain more in the ability to throw heavy for caliber bullets then a moderate 140 grain pill.
     
  11. MudRunner2005

    MudRunner2005 Well-Known Member

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    This is also a big advantage. The extra boiler room and shoulder design help in rease velocities and allow you to throw the big pills at good velocities.
     
  12. tbrice23

    tbrice23 Well-Known Member

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    I think I am going 270 ai. All I have to do is call Douglas and tell them I want AI instead of 270 win. they will receive my action probably tomorrow. Forming will be a lot easier than 280 also. My friend owns a shop in TN and is going to call his supplier tomorrow who keeps AI dies.
    I called Redding and RCBS today. Redding has them in stock but won't sell to me. I'd have to buy from Midway and she confirmed 8 to 10 weeks! I considered the 270 Sherman with Rich but Douglas will aleady have my action by tomorrow.
     
  13. MudRunner2005

    MudRunner2005 Well-Known Member

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    Actually, .280 AI would be alot easier, since Nosler sells .280 AI brass already pre-formed.

    But since you already have two 7mmRM's, I would say go with something a little different.
     
  14. FEENIX

    FEENIX Well-Known Member

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    Excellent choice! My current accuracy load for my .270 AI for 175 Matrix VLD is 2993 FPS out of my 30" Lilja 1:8 3-groove.

    If you change your mind later, you can always convert it to a Sherman for an additional 100 FPS or so IIRC.

    Good luck!