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  1. #1
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    Default what makes a bullet tumble?

    I had some bullets tumble at 100 m from my no 4 today - what would make this occur?

    thanks
    Dulce et decorum est
    Pro patria mori.

  2. #2
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    Default

    travelling to slow to stablelize to light or short will do the same. can also be to long for that rifles twist. Damaged crown leaded barrel rusted barrel or copper fouled. Take your pick. Most likely needs a very good clean

  3. #3
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    Default Not Quite Tumbling

    BB-
    I saw some ultrahighspeed film of an artillery shell leaving the muzzle of a howitzer a long time ago, maybe I can describe what happened----

    As more and more of the shell's bearing surface left the barrel, the tip of the spinning shell started to rotate around the line of trajectory. When it finally popped out, there was quite a bit of rotating yaw at the tip of the shell and very little at the base. The shell at that point was describing a spiral course around the line of trajectory.

    So a crown defect, of whatever kind, which allows the bearing surface to come free on one side before the other, which allows gas to escape past the bullet unevenly, is going to make this wobble worse. Maybe bad enough that the wobble never stops at all.

    Then there's whatever a two-groove barrel does to boat tail bullets---wobbling bullets are a classic feature of this combination.
    Personally, I think some of the two groove barrels give a little tic to the boat tail just as the bearing surface leaves the barrel---but I can't prove it.
    -----krinko

  4. #4
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    Default

    In addition to what Bindi2 stated, worn barrels and worn crown/muzzle will cause bullet tumble, with boat tail bullets making it even worse. Flat base bullets when fired in a worn barrel tend to expand and fill the bore and a boat tail bullet does not expand as well to fill the bore. If the crown is worn and has gas leakage, the escaping gas can push on the boat tail and destabilize it making it yaw and tumble.

  5. #5
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    Default

    Military projectiles show lead at the base this allows the pressure to open the base of the projectile to seal in the barrel. Civve projectiles are flat based copper jackets. Highland 174gn FMJBT are a good copy with a boat tail. This also highlights the shortness of contact area to the barrel. As the barrel wears more expansion of the bullet is required hence the the design used very simple. Talk to your local bullet maker supplies available june july

  6. #6
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    Default long and the short of it is.....

    If your barrel is past its prime...maybe corroded or badly worn....the flat base ones are the ones to go for.... In Oz its hard to beat 170 flat base TAipans.

    If your barrel is in 'new' condition then go for the 174 Grain Sierra match kings as being about the best.

    Alternatively if you can get 'em just use the 170 grain Taipans for everything and you wont go far wrong.

  7. #7
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    Default

    Quote Originally Posted by whiterider View Post
    If your barrel is past its prime...maybe corroded or badly worn....the flat base ones are the ones to go for.... In Oz its hard to beat 170 flat base TAipans.

    If your barrel is in 'new' condition then go for the 174 Grain Sierra match kings as being about the best.

    Alternatively if you can get 'em just use the 170 grain Taipans for everything and you wont go far wrong.
    For the Americans reading this and wondering what the hell Whiterider is talking about (Taipan bullets) just buy Hornady 174 grain round nose bullets for your Enfields, they shoot very well in worn barrels.



  8. #8
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    Default

    Edward,
    Where can we buy these Taipans?

  9. #9
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    Default

    Quote Originally Posted by reddog View Post
    Edward,
    Where can we buy these Taipans?
    Reddog

    Read my lips, I’m American and Whiterider is Australian, Tipan bullets are sold in Australia and Hornady bullets are made and sold in the USA.

    P.S. Drink more coffee.

    P.P.S. Whiterider and I are retired and have nothing better to do than give each other a hard time.



  10. #10
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    Default

    Yer you two take the pain out of a long day. Good humor with good info keep at it

  11. #11
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    Default

    Just why do i have to buy AUSTRALIAN prilgrim????
    So i can buy AMERICAN mate
    Hornady Sierria Fedral ruger remmington winchester etc etc etc

  12. #12
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    Default I've had some really outstanding

    results with the 174 Grain Sierra Matchkings in a No.1 Mk 111 target rifle with a brand new Lithgow Heavy barrel. Groups that you had to look at a few times to believe. The load was Canadian military cases ( 1942) with 41 grains of 2208 (Varget) and CCI primers. Loaded to 'magazine' length.

    On one occasion I got 5 shots into slightly under 2 inches from the bench at 200 yards. That rifle is so good I put it away against the day when I can no longer see the 'military' sights and have to go the girly way and use Central sights.... :-)

    Hopefully that day is a long long long way off...... :-) So yeah, the quality of the 174 Grain boat tail Sierra Matchking is right up there.

    There is also a guy here in Victoria (Bruce Bertram) who makes custom bullets and cases for all sorts of weird calibers. He also makes a 168 grain open point 303 projectile. Havent done a lot of testing on it yet, seems ok so far at least up to 300 yards) but its freely available (from him) and he does a lot of exporting to the USA.

    And no, I have no links to him or his company, didnt marry his daughter or look fondly at his wife...etc etc usual disclaimer.

  13. #13
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    Default

    Mr Ed HORTON. You buy our lithgows we buy your Savages and LBs. I see by the last auction over here somebody scored a LB#4mk1*T with a Lyman Alaskan scope. But then i hear somebody has a Pratt and Whitney stamped Lithgow in the USA o well what goes around comes around i will keep looking.

  14. #14
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    Talking Tight

    Quote Originally Posted by whiterider View Post
    results with the 174 Grain Sierra Matchkings in a No.1 Mk 111 target rifle with a brand new Lithgow Heavy barrel. Groups that you had to look at a few times to believe. The load was Canadian military cases ( 1942) with 41 grains of 2208 (Varget) and CCI primers. Loaded to 'magazine' length.

    On one occasion I got 5 shots into slightly under 2 inches from the bench at 200 yards. That rifle is so good I put it away against the day when I can no longer see the 'military' sights and have to go the girly way and use Central sights.... :-)

    Hopefully that day is a long long long way off...... :-) So yeah, the quality of the 174 Grain boat tail Sierra Matchking is right up there.

    There is also a guy here in Victoria (Bruce Bertram) who makes custom bullets and cases for all sorts of weird calibers. He also makes a 168 grain open point 303 projectile. Havent done a lot of testing on it yet, seems ok so far at least up to 300 yards) but its freely available (from him) and he does a lot of exporting to the USA.

    And no, I have no links to him or his company, didnt marry his daughter or look fondly at his wife...etc etc usual disclaimer.
    barrels and boat tails a very good combo other wise back to the military style when accuracy drops off and hey presto good as new. I also have a feeling that a smaller chamber in the mix has an effect as well. I have a #4T with a tighter chamber than any thing else :D

  15. #15
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    Default well.....tight butts...small chambers...

    ooopss...or was it the other way around.... :-) I'll check with Edward about that one....

  16. #16
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    Default

    [QUOTE=Edward Horton;334577 Drink more coffee
    [QUOTE]

    You are right on. I blew through the words in the post after being mesmorized by that splendid 5 shot group which I assume was shot offhand.

  17. #17
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    Talking

    Bindi2,
    You don't buy LB's from Mr. Horton's (US) reserve, you steal it from ours (Canadians).
    Last edited by Baribal; 05-12-2008 at 08:35 AM.
    Coagula / Solve

    Baribal; http://en.wikipedia.org/wiki/Baribal

  18. #18
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    Cool

    Yeah, we'll I have a nice 1917 Lithgow, and it's staying right here in the US!

    Let me translate, "Well, mate, Ahv gut a 1917 Lithy 'n she's stain rot hare in th' Unotted Stets!"
    Nothing worthwhile ever comes easily.

  19. #19
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    Default

    Seriously,

    For dynamic stabilization, here's a very good link;
    http://anarchangel.blogspot.com/2007...mythology.html

    You can also refer the Kneubuehl's work on ballistics (gyroscopic stabilization of a bullet), but this is scientific stuff and might be hard to follow if you are not a fan of Isaaac Newton.

    In short, he shows that too-long-for-twist-rate (whatever the weight of it) bullets will not going to be stabilized so it will thumble.
    There is also the way the weight is distributed in the bullet (whatever it's rarely seen, especially with modern hot bonding core to the jacket of the bullet - but rarelly happen with "compound core bullets" i.e. steel-lead) but this can occur if you have an "overbore" barrel and a very long leade, because this can cause the engraving of the rifling to be uneven (To know if this is the cause, try to find a spent bullet, look at it carefully, you will find that the grooves on the bullet are longer on one side this it is on the other).
    Coagula / Solve

    Baribal; http://en.wikipedia.org/wiki/Baribal

  20. #20
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    Default

    I ain’t shooting no stinking Commie Pinko Chinese bullets that got lost in Australia in MY Enfield, I don’t care what that old, old, old, old Australian pilot has to say.


    A tai-pan was an influential foreign businessman doing business in China or Hong Kong in the 19th century. The Chinese term is now used in a more general sense for business executives of any origin. The Chinese term literally means big class which is equivalent to the English term big shot.

    Go ahead Whiterider, “hit me” !


  21. #21
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    Default

    The point of the projectile rotating around the line of trajectory is called nutation.

  22. #22
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    Default

    Quote Originally Posted by John Sukey View Post
    The point of the projectile rotating around the line of trajectory is called nutation.
    Mr. Sukey

    Your posting is one of the reasons why the Australians think we need to eat Vegemite, they think all Americans have poor eyesight.

    Please look at the forth posting down in this thread and think about eating more carrots, you are suffering from poor eye nutrition
    (not to be confused with nutation)




  23. #23
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    Default ha ha good one Edward....

    Quote Originally Posted by Edward Horton View Post
    I ain’t shooting no stinking Commie Pinko Chinese bullets that got lost in Australia in MY Enfield, I don’t care what that old, old, old, old Australian pilot has to say.


    A tai-pan was an influential foreign businessman doing business in China or Hong Kong in the 19th century. The Chinese term is now used in a more general sense for business executives of any origin. The Chinese term literally means big class which is equivalent to the English term big shot.

    Go ahead Whiterider, “hit me” !


    Of course a Taipan is also a horribly deadly snake out here.....has been known to inflict fatal bites on ex USAF shirtlifters......

  24. #24
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    Default yes Reddog....

    [QUOTE=reddog;335602]
    Quote Originally Posted by Edward Horton;334577 Drink more coffee
    [QUOTE

    You are right on. I blew through the words in the post after being mesmorized by that splendid 5 shot group which I assume was shot offhand.

    Edward shot that group offhand at 200 yards, one handed, in a howling gale while holding Skennertons book in the other hand....and all the time making rude remarks about Australian coachwood forends exploding......

  25. #25
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    Red face Sorry

    Quote Originally Posted by Baribal View Post
    Bindi2,
    You don't buy LB's from Mr. Horton's (US) reserve, you steal it from ours (Canadians).
    It was won in a raffle:D
    Bones you look after that old lady for us Aussies so her mates can visit:D

  26. #26
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    Default Don't worry, Bindi2

    Our Gvt can be as stupid as yours... might be a Commonwealth brainworm (surely some kind of neurocysticercosis - first sign is a will for a complete ban of firearms)and just give away our jewels...
    Take good care of them, these oldies need exercise and a good diet.
    'Sure it likes Kangaroo and Dingo meat... maybe even rabbit... 'cos they're now said to be too old for two legged games....
    Coagula / Solve

    Baribal; http://en.wikipedia.org/wiki/Baribal

  27. #27
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    Default

    Quote Originally Posted by Bindi2 View Post
    It was won in a raffle:D
    Bones you look after that old lady for us Aussies so her mates can visit:D
    Aye, aye, mate. If only she could speak... I'd need one of you to translate!
    Last edited by bones92; 05-13-2008 at 09:32 AM.
    Nothing worthwhile ever comes easily.

  28. #28
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    Thumbs up Will try

    Quote Originally Posted by bones92 View Post
    Aye, aye, mate. If only she could speak... I'd need one of you to translate!
    If that is a 1 on the top of breech= 1MD or Queensland
    75743 on butt should be the same # on bolt and barrel and bayonet lug unless it is a replacement; 4/41 is usually a into stores type date so could have had a repair and gone into store.Pity about the unit disc.
    Stars are inspector marks.
    Is that a poorly stamped D^D =Australian Department of Defence or D^P which could be Drill purpose?: Hope it is just a poor stamp

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