257 ai

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by royroath, May 13, 2013.

  1. royroath

    royroath Member

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    I am having a custom rifle built in 257 AI. I have acquired a 270 Rem 700 because I want a longer action than the regular 257's have. What is the best AOL for this configuaration that gives more powder capacity but assures enough bullet contact in the case?
     
  2. MudRunner2005

    MudRunner2005 Well-Known Member

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    It oughtta be wicked, but you got me stumped on this one...Never have done much research into the .257 AI. I looked at it a little bit before I got my .257 Wby, but decided to go with the Weatherby, just b/c I had always wanted one. That .257 AI oughtta be a shooter that's for sure. Good luck on your quest. And keep us updated.
     

  3. royroath

    royroath Member

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    Thanks for the reply. I suspect the bullet length will cause some variation but since the bullet is lighter and shorter than the 270, the AOL will certainly be shorter. Perhaps someone has a recommendation for the minimum safe distance the bullet will need to be seated in the case.

    Roy
     
  4. MudRunner2005

    MudRunner2005 Well-Known Member

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    I like the Berger 115 VLD's and Nosler 110 Accubonds out of my .257 Wby. However, Wby has freebore, so I just seat mine to magazine length to make it a repeater since I hunt with that rifle alot, and like to have more than 1 shot in there. It will all just depend man, some rifles like them seated up against the lands, some like them slightly further away. You'll just have to test it out to see. I'd try seating them about 0.003-0.005" just inside the magazine's internal length. It might like them shorter than that, but that's where I'd start if it were my gun. But I'm also not any kind of an expert....But that's just where I'd start. Some folks say for start 0.100" and work your way longer to see what it likes. Everyone has a different method.
     
  5. shortgrass

    shortgrass Well-Known Member

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    If you're talking about the .257 Roberts/Ackley Improved, you'll have all the mag length you might ever use in a LA. Without knowing how much throat the chamber will have it is imposible to guesstimate a OAL. I'd suggest you aquire a Hornaday OAL Gauge and have your 'smith fix you up with a .257 A.I. case altered for it. Not every rifle requires the bullets to be seated into or on the lands to be accurate.
     
  6. royroath

    royroath Member

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    Shortgrass: Thanks for the reply! I am sending a empty case with the new barrel to have it reamed at the gunsmith. I know I have at least 3.3" in the AOL in the mag but want to make sure I have enough a seat depth with the bullet to be safe. Any guesses?
     
  7. shortgrass

    shortgrass Well-Known Member

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    Don't like guesses, try to deal only in fact!
     
  8. TOM H

    TOM H Well-Known Member

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    What you need to do is make up some dummy rds with bullets you want to use beside AOL you have to consider how far off the lands you want. Might want to talk to your gunsmith see what he has to say.