Fluted Barrel on Big Bore Rifle

Discussion in 'Firearms & Ammunition' started by Stan-Elephant Trail, Nov 2, 2012.

  1. Stan-Elephant Trail

    Stan-Elephant Trail AH Veteran

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    Calling all experts. I am planning to build a rifle in either .458 Lott or 50 B&M and thinking of having the barrel fluted. Kindly tell me pros and cons on this subject please.

    Thanks,

    Stan
     
  2. James.Grage

    James.Grage GOLD SUPPORTER AH Legend

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    Some points i picked up...
    The only real benefit is that it allows you to remove weight out on the front end of a rifle wearing a long, heavy contour barrel for rifle balancing purposes.

    The other thing I can think of is faster heat dissipation due to the larger surface area, but target shooting is pretty slow paced so again it seems redundant.

    Fluting increases surface area, so a barrel does cool faster. It also reduces weight and maintains the structural strength of a bull-barrel the same diameter as the the outer-diameter of the flutes.

    If it is done correctly, it gives you a cooler, stronger barrel for less weight. The flutes must be indexed properly for even spacing, and should only be done by someone who knows what they are doing.

    Lilja and Hart both rifle their barrels using the button riflling method. With button rifled barrels, the fluting MUST be done after the barrel is rifled, and removing metal from the barrel exterior causes changes to the bore dimensions. With a cut rifled barrel such as Krieger, Obermeyer, and Mike Rock, the barrel is bored, then the barrel is fluted, and finally the bore is reamed and rifled. So, any changes to the bore thru fluting are irrelevant, since the barrel is reamed and rifled to the proper dimensions AFTER the fluting is done.

    Anyway, the article showed the effects of fluted barrels and the amplitude of barrel vibration, and the conclusion was that fluting doesn't help the barrel's accuracy at all. That is, fluting a barrel makes it less stiff. Laws of physics and mechanical engineering formulae describe it quite well. However, for barrels of the same weight, a fluted barrel has less vibration amplitude.

    So, if you're going to have a barrel that weighs x lbs, if you flute a heavier (larger diameter barrel) so that it now weighs x lbs, it will be slightly more accurate than an unfluted barrel that weighs x lbs.

    The misunderstanding is that you can improve the accuracy of a barrel by fluting it. That just isn't true.

    Varmint Al's Fluted Barrel Stiffness Analysis
    CONCLUSION ON BARREL FLUTING....

    *

    When comparing two barrels of equal weight, length, and material but one is solid and other is fluted, the fluted barrel will have:
    o

    A larger diameter
    o

    Greater stiffness (depending on how the extra diameter/weight is distributed)
    o

    Vibrate at a higher frequency (depending on how the extra diameter/ weight is distributed)
    o

    Less muzzle sag (depending on how the extra diameter/ weight is distributed)
    *

    Fluting a solid barrel will:
    o

    Reduce its weight
    o

    Reduce its stiffness
    o

    Increase its natural frequency of vibration
    o

    Decrease its muzzle sag.
    *

    Reducing the weight of a barrel by fluting makes a stiffer barrel than reducing the weight by decreasing its diameter.
    *

    A shorter barrel of the same section, solid or fluted, will sag less and vibrate at a higher frequency.



    More info on barrel dynamics...
    Barrel dynamics... FEA Barrel Pressure Analysis on a 6PPC Rifle Barrel
     
  3. James.Grage

    James.Grage GOLD SUPPORTER AH Legend

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  4. Stan-Elephant Trail

    Stan-Elephant Trail AH Veteran

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    Hi James,

    Thank you very much for a very detail information. I do highly appreciated your help.

    Stan
     
  5. Stan-Elephant Trail

    Stan-Elephant Trail AH Veteran

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    James,

    After studying your cooment and the article, I think I would be better off with a sport contour.

    Thanks again and please have a nice weekend.

    Stan
     
  6. 1ObsessedHunter

    1ObsessedHunter AH Veteran

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    Don't do it...barrel fluting is very overrated. Many barrel makers and gunsmiths have jumped on that bandwagon just because customers think it looks cool and are willing to pay for it. Many top gunsmith will not recommend it. If not done properly it can create stresses in the barrel and reduce accuracy. Also, and think about this, the purpose of fluting was to increase surface area by creating these concave flutes down the barrel in order to dissipate heat. But, by removing barrel steel you're effectively reducing the size of you're barrel's contour and the barrel heats up faster, also reducing accuracy....Good Luck!
     
  7. Stan-Elephant Trail

    Stan-Elephant Trail AH Veteran

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    Thank you 10bsessedHunter. You have just re-confirmed my decision after reading James's comment and article. i will not do it.

    Stan
     
  8. enysse

    enysse AH Ambassador

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    Interesting stuff on fluted barrels, thanks guys!
     

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