260 Ackley Improved Load data and velocity information

Discussion in 'Reloading Forum (All Calibers)' started by Cedarcreek, Sep 2, 2010.

  1. Cedarcreek

    Cedarcreek

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    I am looking at a 260 AI project, I am having a hard time finding load data to determine what the velocity advantages are over the 260 remington.

    I will be shooting a Shilen barrel, 27" long with a 1-8 twist.

    I Plan on trying 142 SMK's, 123 SMK's, 139 Scenar and 123 Scenar in that order.

    Any info would be appreciated.
     
  2. Cedarcreek

    Cedarcreek

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    No one willing to help with 260 AI?
     
  3. RonAKA

    RonAKA

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  4. Cedarcreek

    Cedarcreek

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    No I will take a look at it
     
  5. Cedarcreek

    Cedarcreek

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    Looks good thanks for the tip on this article.
     
  6. RonAKA

    RonAKA

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  7. oldfart

    oldfart

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    In my 260ai I am getting 2800 fps with 48.2 4831sc, RP brass, Wolf LR mag, and SMK 142.
     
  8. Cedarcreek

    Cedarcreek

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    RonAKA- Thanks for the links, good info.
     
  9. texote

    texote Site $$ Contributor

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    Old topic

    Can you get a 140gr bullet to 2950 in the Ackley?
     
  10. jcampbellsmith

    jcampbellsmith Site $$ Contributor

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    Search for 260 Ackley on this forum, there's quite a bit comes up, but as far as I can see, I'm not sure it is worth all the bother. I've had std 260 Remingtons since '99 and I've read a bit on both the 30 degree and 40 degree improved options, but the benefits appear to be marginal.

    Have fun. JCS
     
  11. savageboy

    savageboy

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    I loved my 260AI, won several relays and matches with it (have since sold due to medical issues). Typical vel for its sweet spot load was 2930FPS w/ H4831SC and 139gr Lapua. Very accurate. I could get higher velocities w/ RL17 but in my set up it wasnt as accurate and flyers increased for some reason.
    Fireforming was a pain, but once you do it, the cases never need trimmed w/ the 40deg shoulder and straight case walls. I fireformed using the COW method.
    Love the round. Mine did what a 6.5x284 does w/ less powder, and hopefully more barrel life.
     
  12. pdog2225

    pdog2225

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    I am working with my new 260AI rifle also. The velocity I'm getting is not up there with what Terry Cross reported. So far I've been able to reach 2900fps using 48.5grs of H4831sc,210M, norma .243 cases (weighs 3.0grs more than RP260) (neck turned,with donut removed)and the 142smk. However the temperature has been an avg of 47° and I'm hoping by the time it gets to 85° or so the velocity will increase to 2925 or so. This is a blueprinted rem 700 action , Kreiger 8.5T, 30"long barrel. I love the accuracy and the small increase in velocity. Right now I have 270 rounds down the tube.
    pdog2225
     
  13. savageboy

    savageboy

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    My velocites were only that high w/ the Lapua 139's. The load it liked w/ SMK 142's were 2887fps.
    I had a 28" Shilen Sel. Match on mine. I had it long throated for the 140's. I sent 2 dummy rounds with my order to Shilen. I was fortunate that the load it liked best w/ the Lapua's was 2930 ish fps. It wasn't quite there till it broke in though.
    Once I added a good rear rest and a better scope- Nightforce 12-42x so I could aim more precisely at 1000yds I went from about the middle of the pack w/ the group of guys I shot with to the upper tier- sometimes winning.
    I had 2 neck surgeries and the prone position w/ anything was brutal. I ended up switching to a 6brx right at 21lbs and that has helped neck issue. I have found the 6brx to be a little more accurate but the 260AI will shoot inside of it in the wind. The 260AI is a great round! I will build another one some day. The rem. brass wasn't that great and really needed to be sorted. I had good success w/ Win 7-08 brass necked down and fireformed. The Lapua 308 brass necked down didn't quite give the velocities of the Win.
     
  14. CaptainMal

    CaptainMal

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    Here's some results from my Rem action & 26" Krieger bbl 260AI. They are not in any special order.
    140 SST - 47.1 gr Rel 22 = 2801
    - 47.6 gr. Rel 22 = 2836
    140 A max - 47.6 gr Rel 22 = 2842
    140 Sierra - 47.9 gr. Rel 22 = 2949
    129 SST 49.0 gr H 4831SC = 2996
    129 SST 49.0 Rel. 22 = 2969
    140 Sierra 45.8 gr. Hunter = 2911
    140 Berger 48.5 gr. 4831SC = 2892

    That's enough. I have literally a full book of test results and now about 960 rds. through the barrel.

    LOSER...Mine is not very accurate with anything and I have tried most everything. Two other friends also have the same caliber and each of them is disappointed. To put it in perspective I'm still hoping to get 1/2 moa groups and have essentially given up. The junk has been sitting in my safe the last 6 months essentially untouched. If I get motivated again it will be motivation with a new barrel but doubt I would do 260 AI again.

    Hope you have better results.
     
  15. Jay Christopherson

    Jay Christopherson sun's out, guns out Administrator

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    You should be able to reach a little over 3000fps (or close to it) with the .260AI and 140grain-class bullets safely and without too much trouble. I run mine at 3020fps, although I have 30" barrel. Take a look at RL-17. RL-19 or 22 will be too slow. On mine, accuracy improved *greatly* once I reached the node at 3020fps.
     
  16. texote

    texote Site $$ Contributor

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    What are yalls fire forming loads?
     

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