Sako AV in .30-06 Ackley Imp

Discussion in 'Sako Long/Magnum Actions' started by stonecreek, Nov 2, 2019.

  1. stonecreek

    stonecreek SCC Secretary Forum Owner SCC Board Member

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    I ran across an early A-V in nice condition which had been rechambered in .30-06 Ackley Improved and was able to buy it at what appeared to be a bargain. I got around to shooting it today with both some standard .30-06 ammunition and a couple of rounds of ammunition I reloaded in fireformed cases. I thought the results, especially as compared to a couple of standard Sako .30-06 rifles could be interesting.

    First I tested velocities of regular Remington 150 grain factory Coreloct. All rifles were Sakos with 24.4 inch factory barrels, including the A.I. rifle. Sako #1 yielded an average of 2891 fps; Sako #2 yielded an average of 2916 fps; and the Ackley yielded 2825 fps for an average loss compared to the regular chambers of 78 fps.


    I also tried one of my preferred handloads of 58 grains of RL17 under a 150 grain Nosler Ballistic Tip with the following results: Sako #1, 2972 fps; Sako #2, 3019 fps; and Ackley, 2922 fps for a loss of 73 fps -- very close to the loss with the Remington factory stuff.

    Finally, I reloaded a couple of rounds in the fireformed Ackley brass with 60 grains of RL17 (two grains more than the standard loads) with a 150 Ballistic Tip. The velocity was 3090 fps, which seems like a big jump for just two extra grains. Bolt lift was normal and the cases and primers showed no visible pressure signs. This gun may have potential.

    When I get time I'll load some additional loads in the A.I. brass to see if the results are repeatable. Thus far I only have five rounds of fireformed brass, however the velocity and accuracy with regular ammunition is fully adequate for anything you might want to shoot. Incidentally, the regular .30-06 ammunition headspaces perfectly in the A.I. chamber with no slop, indicating that the re-chambering job was well executed.

    Maybe I did get a bargain.

    Here is a photo of a fireformed case on the left with a standard case on the right.

    DSC01980.JPG
     
    Sean Hodges likes this.

  2. kevinlg

    kevinlg Well-Known Member

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    Shooting a factory round.......one of Ackley's design advantages. Chamber headspace should be factory minus 0.004", for the 40 degree A.I. shoulder angle.

    Sounds like you got a good'un.:)
     
  3. CVCOBRA1

    CVCOBRA1 Well-Known Member

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    As long as you have the easy bolt lift it sounds like you have a keeper. P.O. just happened to know what he was doing. I would say Roy took a lesson from his play book. Great to see.
     
  4. stonecreek

    stonecreek SCC Secretary Forum Owner SCC Board Member

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    The Ackley design makes a lot of sense, but people often expect too much of it. Lots of folks think in terms of a 200 fps velocity boost or something of that nature. They sometimes achieve it, but only at the expense of greatly increased pressure.

    The roughly 75 fps drop in velocity with standard .30-06 loads compared to a standard chamber is a good indicator that, loaded to a similar chamber pressure as a standard .30-06, you can expect about a 75 fps increase with the Ackley case. This is arguably a useful increase in velocity, but reaming a chamber out to A.I., which increases case capacity by 5 to 10 percent, won't turn a rifle into a belted magnum with 25% more case capacity.

    I don't think I'd ever bother to have an Ackely Improved made from one of my rifles (who wants to mess up the originality of a Sako, anyway?) However, the "improvement" knocked about $200 off of the market value of the rifle I bought, so I'm doubly benefiting from the previous owner's modification.
     
  5. kevinlg

    kevinlg Well-Known Member

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    Agreed...Stone.

    I believe that P.O.'s "best" AI is the 250AI(it nips at the heels of the 257Bob).......and I just so happen to have loooong planned idea of putting a round-top L579 action in an older Deluxe stock, with a nicely blued sporter barrel.

    Question is......will I live that long. :)
     
  6. stonecreek

    stonecreek SCC Secretary Forum Owner SCC Board Member

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    Yeah, a lightweight .250 Savage, either standard or improved, on an L579 with a slender and fairly short barrel would get me salivating, too.

    I'm not sure what all of the fuss and hype over the 6.5 Creedmoor is about, but it is simply a .250 Savage Ackley Improved necked up by .007", just with a 30 degree shoulder instead of Ackely's 40 degree shoulder. Seems like Ackley had already "invented" the Creedmoor -- all he lacked in making it hugely popular was an advertising budget and the internet.
     

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