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Thread: optimum barrel length for a .243 build

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    optimum barrel length for a .243 build

    I am looking for input for what the optimum length should be for a .243 build I am doing.
    Im using a shilen 28" match grade blank.
    Im not sure that the .243 needs any longer barrel than a 24" but im just not sure.
    I guess im trying to be as efficient as I can with the .243 cartrige.
    I'll be shooting 105 a maxes in it and am looking for the max velocity and dont want barrel length to be the limiting factor.
    " You may find me dead in a ditch somewhere. But by God, you'll find me in a pile of brass." -Seal of Honor

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    Re: optimum barrel length for a .243 build

    This is a good place for Info on the .243

    http://www.6mmbr.com/243win.html
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    Kevin


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    Re: optimum barrel length for a .243 build

    Thanks!
    " You may find me dead in a ditch somewhere. But by God, you'll find me in a pile of brass." -Seal of Honor

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    Re: optimum barrel length for a .243 build

    For the heavies no shorter than 26"

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    Re: optimum barrel length for a .243 build

    At least 24" of rifling.

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    Re: optimum barrel length for a .243 build

    You definitely want longer than 24", especially if weight isn't an issue. I had the exact same dilemma when designing my 6mm rem improved. I looked at lots of test results comparing velocity to barrel length and in the end I went all out and got a big 32"!
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    Re: optimum barrel length for a .243 build

    Mine is 24" right now and I will be re-barreling at 26-27" when it comes time. I think it would really optimize H1000 with the 115's. Right now I am at a comfortable 2950 and it would be nice a move them out a bit fast without pushing things harder. Shooting in the evening it is obvious there is definitely a bit of unburnt powder.
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    Re: optimum barrel length for a .243 build

    what are going to use it for? i run mine 22-23 tops give up 50ish FPS for handy everytime . Mine are the AI'ed version 3250 with 105 amax is plenty. R-17 is were its at...........this is a 23 tripped but 3250 with the 105


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    Re: optimum barrel length for a .243 build

    No doubt RL-17 will get you top speed but the temp sensitivity of that powder is ridiculous. To the OP I agree with others that at least 26" is needed to optimize but really if weight is not a concern I would use all 28". You can always cut 2" off If see the 28" barrel is just to long.

    Dustin

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    Re: optimum barrel length for a .243 build

    Depends on use, longer barrel is going to give you more velocity. All things being equal, longer is more velocity no matter how you slice it.

    Efficient as in knee of the curve or efficient as in squeezing out every last bit of fps you can?

    If hunting rifle then you need to find happy medium between barrel length and ability to use rifle in field.

    243 w/heavy bullets you'll want to go as long as possible. You could go to 36" - 38" barrel and still be gaining velocity. That isn't practical.
    You have a 28" blank, I'd finish it as long as possible which will be 26 to 27" depending on how much the smith feels he needs to cut off each end. Even at 28", you are going to be velocity limited by the barrel length. 15-20 fps/in so you aren't giving up all that much but you are giving up some.
    30" barrel vs 24" barrel you'll be giving up 90 to 120 fps. 27" barrel vs 24" barrel you'll be giving up 45 to 60 fps. Even at 120 fps that isn't enough difference in velocity to make up for a blown wind call.

    F-class rifle, go long as you possibly can.
    Field rifle, find a happy medium that works for type of shooting you'll be doing.


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    Re: optimum barrel length for a .243 build

    I would like my muzzle velicity to be up to or past 2900fps.
    " You may find me dead in a ditch somewhere. But by God, you'll find me in a pile of brass." -Seal of Honor

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    Re: optimum barrel length for a .243 build

    Also do any of you have any good loads that I might start out with that would give me at or near that velocity with the 105's?
    Thanks!
    " You may find me dead in a ditch somewhere. But by God, you'll find me in a pile of brass." -Seal of Honor

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    Re: optimum barrel length for a .243 build

    My GAP has a 27 for 115DTACs.

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    Re: optimum barrel length for a .243 build

    Guess I just built mine to short! Figures, hate you guys!
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