257 AI Load data

Discussion in 'Reloading' started by dabrown56, Oct 11, 2018.

  1. dabrown56

    dabrown56 Active Member LRH Team Member

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    Is there a GOOD source for 257 AI load data? Just got a 257 AI and I am looking for reliable tested data to start with. Will probably be using various 100 to 120 gr bullets.
    Thanks
     
  2. MudRunner2005

    MudRunner2005 Well-Known Member

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    If you scroll down, you will see where you can choose which weight bullet you are looking for data on...

    https://load-data.nosler.com/load-data/257-roberts-ackley-improved/

    I recommend Berger 115 VLD's, Varget powder, and either Fed 215M or CCI BR2 primers.

    If you ever rebarrel, go with a 1:7 twist and try those new Blackjack 131 ACE bullets.
     
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  3. Heavyiron

    Heavyiron Well-Known Member LRH Team Member

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    Start at max on 257 roberts data and work up from there.
     
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  4. MagnumManiac

    MagnumManiac Well-Known Member

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    ^^^^^^^this^^^^^^^

    In mine (now re-barreled to 338-06) I used a lot of 760, H4350 and H4831sc. Dabbled with RE19/22 and 780 (Supreme).
    760 and H4350 ran so close in velocity and group size that I often had to check to see what powder I was actually using on the day, POI was very close together too.
    I mainly used 100gr BT’s, 100gr Speer HotCors and 110gr Accubonds.
    I had a load with 115gr Partitions that I think I used less than 20 rounds of the 50 I made for deer, shot 17 animals and think 1 had 2 shots in it to bring it down, the first shot was a little far back from memory.
    Of the powders I mentioned, 760 and H4350 were by far the standouts, same goes in my 338-06 actually.

    Cheers.
     
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  5. dabrown56

    dabrown56 Active Member LRH Team Member

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    I'd like to thank everyone for their feedback, I will look up the references and take all of this into consideration when I start working up my loads, thanks again.