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Thread: How a muzzle device works to enhance accuracy

  1. #11

    Friend Deveng

    Quote Originally Posted by Deveng View Post
    Hi Bill

    PedroS had the same idea to put a MD and see what happens.

    You need to look at the photo with a bit of imagination, I adjusted the weight by adding and removing some Blue Tack Plasticine from the top.

    This moved the node to the end of the welding rod.

    Also every time I added some weight the resonant frequency decreased and finally it reduced to 21Hz.

    This would mean that putting a MD on a barrel it would also slow down the rate of the vibrations and in this instance it slowed them down 41.6%.

    Attachment 1499


    Attachment 1500

    Regards
    Graham

    _____________________________



    Friend Deveng:


    This amazing picture confirms what I discovered almost 30 years ago, when I developed the first muzzle device.


    A muzzle device is used to stop the muzzle of a gun barrel, one time, thereafter is has no further function.







    Graham, I like the way you designed your MD so it reveals the end of the rod......very clever.

    ____________________________


    Also, although you've confirmed the "stopped muzzle", there's a whole bunch of folks who are not going to be happy.


    For the past almost 30 years now, a bunch of folks have decried the stopped muzzle........as impossible.


    One of the leading naysayers is my good friend Geoffrey Kolbe......


    Geoffrey, former owner of Border Barrels, Scotland, is the individual who developed the ridiculous compensation theory.


    His ridiculous compensation theory spawned a ton of similarly ridiculous "tuning" theories.



    ___________________________



    Graham, I'm going to ask Wally to make all these barrel vibration threads, including all of your work and pictures, a 'Sticky".


    All of this must be preserved, forever.


    Your friend, BC


    ________________________________


    PS:


    I have an additional comment to make about this incredible picture of yours.....


    But, I'll make it on another thread, using your picture and comments as the introduction.


    Also, friend Anthony DiOrio: You most certainly must add this picture to your list......
    Last edited by Bill Calfee; 1 Week Ago at 01:39 PM.

  2. #12
    Quote Originally Posted by Bill Calfee View Post
    _____________________________



    Friend Deveng:


    This amazing picture confirms what I discovered almost 30 years ago, when I developed the first muzzle device.


    A muzzle device is used to stop the muzzle of a gun barrel, one time, thereafter is has no further function.







    Graham, I like the way you designed your MD so it reveals the end of the rod......very clever.

    ____________________________


    Also, although you've confirmed the "stopped muzzle", there's a whole bunch of folks who are not going to be happy.


    For the past almost 30 years now, a bunch of folks have decried the stopped muzzle........as impossible.


    One of the leading naysayers is my good friend Geoffrey Kolbe......


    Geoffrey, former owner of Border Barrels, Scotland, is the individual who developed the ridiculous compensation theory.


    His ridiculous compensation theory spawned a ton of similarly ridiculous "tuning" theories.



    ___________________________



    Graham, I'm going to ask Wally to make all these barrel vibration threads, including all of your work and pictures, a 'Sticky".


    All of this must be preserved, forever.


    Your friend, BC


    ________________________________


    PS:


    I have an additional comment to make about this incredible picture of yours.....


    But, I'll make it on another thread, using your picture and comments as the introduction.


    Also, friend Anthony DiOrio: You most certainly must add this picture to your list......

    Howdy Bill,
    Glad this is now a "sticky".

    That picture of Graham's experiment is pretty impressive. There will be naysayers. They will disparage that picture.

    But there it is!

    They will try to say the muzzle is changing directions or "nodding". That picture is problematic for that argument, especially since the barrel moves substantially less than that rod does in the experiment. You have said, and even had an engineer once agree with you that the barrel only moves about .004 of an inch, correct me if I'm wrong, please.

    A rifle barrel is much thicker than the welding rod. It will flex much less than the welding rod. The welding rod experiment does not just give a visual, it exagerates by several times what's going on, and yet, look at the tip of the welding rod in that pic. If the tip of the welding rod can be stopped..........so can the tip of the barrel.


    I'm glad Graham found a way to capture what's going on with that picture!

    Take care,

    Greg

  3. #13
    Quote Originally Posted by Deveng View Post
    Hi Bill

    What do you think is the reason that causes the barrel to vibrates in the first place.


    A barrel still vibrates up / down and left / right even when clamped in a sliding bearing such as in a ammo testing tunnel.

    In such a sliding bearing it can only slide backwards dead parallel to the barrel (checked with a dial gauge) this compensates for any sagging of the muzzle.

    Also the center of mass is inline with the bore similar to what I suspect they do in a rail gun.

    The pressure acting on the bullet is concentric and symmetrical so may expand and stretch the barrell.

    Regards
    Graham
    Graham, I'll take a shot at explaining part of this. Can't promise I'm correct, so you are welcome to let me know if I have it wrong.

    Bill once explained the beginning of barrel vibrations as being the beginning of everything after the pulling of the trigger. If I am paraphrasing him correctly. The moment the sear breaks vibrations begin traveling to and through the barrel. More vibrations happen when the firing pin hits. More as ignition begins. As I understand it, the start of recoil, which is somewhat retarded by the recoil lug, or tang of a rimfire action, would contribute to vertical vibration, and substantially more so than lateral vibration.


    Not saying I am correct, but that is my understanding of it.


    Take care,

    Greg

  4. #14

    Thanks

    Hi Greg

    Yes in my eyes you are correct.

    It really is about the magnitude of the various vibrations and if they have a significant effect.

    Maybe I should have ask the question a little different.


    I have spent a bit of effort finding and isolating the various sources of vibration that could affect the flight of the bullet.

    I see it affecting the flight mainly just as the bullet leaves the barrel. (there are several other things happening at this time as well)


    The firing pin thing is a bit interesting as it does produce a vibration , I can detect it but too small to measure.

    Also the firing pin would causes other things to happen.

    The recoiling of the contraption was my first thought for the major cause of the vibration by as described by Varmint AL "The recoil and bullet motions "pulls" the rifle barrel to a new shape" this is by moving back and rotating about the center of gravity. He has a good little video of this.

    But when I reduced the rotating about the center of gravity thing there was still a major vertical vibration.

    And as far as vibrating left to right, where that comes from I don't know.

    I actually see these things as clues to something is happening and we don't know what.

    Thanks again for answering

    Regards
    Graham

  5. #15

    CYA friends

    CYA friends


    This is the most important photograph about barrel vibrations, and how a muzzle device is used to control them, in the recorded history of the advancement of rimfire accuracy.






    When I first saw this amazing photograph, yes I was astonished, like everyone else.


    But............


    As soon as this amazing photograph has time to fully soak in, I'll have an additional comment to make about what this amazing photograph truly represents.


    To do so I must do a doodle......


    Which I'll try to do soon...



    Your friend, Bill Calfee
    Last edited by Bill Calfee; 5 Days Ago at 09:22 PM.

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