rifling... can it be done?

Discussion in 'New project ideas' started by thegodofhellfire, Apr 14, 2013.

  1. thegodofhellfire

    thegodofhellfire New Member

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    been watching lately and i'm not sure if it's ever been done.<br>but a simple, small, shoulder fired, high velocity shooter with a rifled barrel.<br><br>rifling it self is probably out of the question because the elastic would have to follow the projectile upon release, therefor continuous rifling in a barrel is impossible. but there must be someway to initiate a spin or twist to a protectile to increase accuracy and lesson drop.<br>maybe twisting the elastic as it's drawn back or some sort of shaped channel pared with a shaped projectile to impart spin upon it.<br><br>can it be done?<br><br>cheers! <img src="http://illiweb.com/fa/i/smiles/icon_pirat.png" alt="pirat" longdesc="23">
     
  2. onnod

    onnod Im from Holland, isnt that weird?

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    giving ammo a spin is pretty easy, but i don't think it is is a rifle...
     

  3. thegodofhellfire

    thegodofhellfire New Member

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    spinning a projectile is easy, yes... they do that on their own because there is no real guide to a shot unless it's an arrow or oddly shaped.<br>but controlled spin?<br>how would you go about giving a projectile proper spin without using some sort of fletching?<br><br>i'm trying to imagine this using a bullet, mini ball or normal lead/steel ball shaped projectile as well. in order to keep ammo a plenty and possibly on the shooter in a feed magazine.<br><br>my first thought would be add an "extra barrel" or rifled tube at the end of the normal track after the band expends it's energy...<br>but after that the projectile is doing nothing but slowing down and it adding all that would just impart more friction onto the projectile and negate any gains in range where the added accuracy is wanted.<br>i'd just like to think up a way to self-stabilize the projectile to increase accuracy at longer ranges.<br><br>i guess it's just all down to the projectile shape itself when it comes to sling shots...<br><br><br>rifling... <br><img src="http://i.imgur.com/VKIXWvj.jpg" border="0" alt="">
     
  4. pelleteer

    pelleteer Middle Aged Delinquent

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    You might be able to do something along the lines of the old Brunswick rifle, which used a belted round ball and two rifling grooves in the barrel. If you were to build something like one of Joerg's devices where the ball is totally enclosed by "rails" on four sides, you could cut straight channels into two of the rails to hold the ball in position as it went through. Then you could have a detachable or hinged "barrel" assembly with corresponding grooves that are slightly helical like rifling. The ball would be dropped down the channel in the main body of the device, then the "barrel" would be hooked onto the end (or swung down on its hinge). When you fired the device, the ball would travel along the straight grooves in the rails until it reached the barrel part, at which point it would follow the helical grooves inside the barrel and it would spin. By the time the ball reached the barrel, the bands and pouch would already have come to a stop. The only things I don't know are: 1. What to make the barrel portion out of, and 2. How to cut helical grooves on the inside surface of it. But something like this could theoretically work.<br><br><a href="http://en.wikipedia.org/wiki/Brunswick_rifle" class="postlink" target="_blank" rel="nofollow">http://en.wikipedia.org/wiki/Brunswick_rifle</a><br><br><br>A mould for belted lead balls could be made, or you could have someone like Jeff Tanner make one for you.<br><br><a href="http://www.jt-bullet-moulds.co.uk/" target="_blank" rel="nofollow">http://www.jt-bullet-moulds.co.uk/</a><br><br>edit: I know this doesn't fit your desire to use a normal round ball or minie ball type projectile, but it's the only way I can think of offhand to get a rotating slingshot projectile. <img src="http://illiweb.com/fa/i/smiles/icon_scratch.png" alt="scratch" longdesc="33">
     
  5. FIAAO

    FIAAO Failureisalwaysanoption

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    Why do you want to spin the ball? As far as I know sphearical bullets do not need any spin as they are, well... Sphearical. Bullets need to have spin in order to not tumble in the air, but a round bullet can not tumble as every side of it is the same. <br><br>But you should look at soft air guns that use "hop up". They make the ball spin "upwards" or "backwards" so the Magnus Effect pushes it up.
     
  6. thegodofhellfire

    thegodofhellfire New Member

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    i use to play paintball quite a bit when and i had a paintball marker with a barrel shaped with a slight "upward slope" or "curve" in the middle of it which gave the round projectile backspin and therefor gave it a further distance and more stable flight allowing for accuracy... it worked quite well using this magnus effect you speak of.<br>but with paintball you're maximum (safe) velocity of a projectile is ~300FPS (feet per second)...<br><br>but what i'm hoping to do is impart a spinning in the same way a rifled barrel gives to a bullet. less to do with increasing range but more to do with stabilizing the projectile to increasing accuracy at effective range... <br><br>i feel as if a bullet or mini-balled shaped projectile exiting a slingshot in that manner would fly a more stable path and longer path than the same object without the spin and help from centrifugal force.<br><br><br>i'm still a bit of a "noob" with sling shots, so i wonder what is the maximum speed a projectile could leave a good slingshot, is it more than one from an air rifle?
     
  7. JoergS

    JoergS Administrator

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    It is really not necessary for heavy, round slingshot projectiles. Inertia takes care of a straight flight. Rifling is absolutely necessary for longitudinal bullets, as those would start to tumble without the rotation. <br><br>However, so many people want to see a rifled slingshot that I have been thinking about giving it a "shot". <br><br>I don't think twisted rubber or a rifled barrel can do that. I am more thinking about a crossbow that I rotate as a whole, with lock, trigger, fork, rubber all rotating. <br><br>The trigger would be pulled with a wireless remote control (parts from cheap RC cars). The rotation would be done by a quality battery drill (like a Makita). <br><br>The only problem I see is that the number of rotations per meter would still be fairly low, even if the drill does 1300 rpm. We are talking about one half turn per meter, tops. I have no idea if that would make any difference at all. <br><br>
     
  8. FIAAO

    FIAAO Failureisalwaysanoption

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    No, an airgun shoots at much higher velocity than a slingshot (In most cases). Just an example: the FXAirgun Verminator Mk II (I think that was the name) shoots an arrow at approx. around 200 m/s (which is a lot! The most powerful swedish legal airgun shoots a little 4,5 mm projectile at that speed, and an arrow is much heavier). Joergs arrowshooting slingshot crossbow shoots at 65 m/s.
     
  9. linuxmail

    linuxmail New Member

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    I doubt that rifling with even be effective at the low velocity produced by rubber or elastomer powered weapons.
     
  10. JoergS

    JoergS Administrator

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    Brian, my thinking exactly. But my reaction: If in doubt - lets test it!
     
  11. Alias Finn

    Alias Finn New Member

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    I think putting a spin on rocks would improve accuracy. SOne people think this is how Rufus hussey was so accurate while shooting stones.
     
  12. Flipgun

    Flipgun Well-Known Member

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    <div>If you were throwing a sling, Then twisted fins on the load may give you the effect you wish. Other wise, cylinder cuts on threaded rods will give the same result I'm thinking.</div><div class="clear"></div><div class="signature_div">
    <br>Failed perception is when you have a gun, I have a slingshot and you think you are the only one that is armed. <img src="http://illiweb.com/fa/i/smiles/icon_lol.gif" alt="Laughing" longdesc="7">
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  13. squidget

    squidget Junior Member

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    <div>would it be possible to "groove" the projectile if using lead balls then grove 3 or 4 "u" shaped grooves equally around an axle point like the way modern motorcycle tires are starting to be grooved im the michelin pilot series.<br>this may cause a "paddling" effect while flying creating an inherent spin lessening drift?<br><br>although a rubber fired projectile in general is slower isn't it as well as they are heavier so weight and the slower speed should give better accuracy wouldn't it? <br><br>lead balls are not very smooth so the dimples in them should also creat a wind resistance aided spin wouldn't they?</div><div class="clear"></div><div class="signature_div">
    <br>:cheers:If in doubt place it between rubber and shoot it <img src="http://illiweb.com/fa/i/smiles/icon_cheers.png" alt="cheers" longdesc="28">
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  14. mhpr262

    mhpr262 Member

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    Spinning up the projectile costs energy which can only come from the energy stored in the rubberbands. Whatever you think you can gain from getting your projectile to spin would be more than offset by the resulting reduction in ammo velocity. Fins are a much more effective and economical way of stabilizing the projectile in midflight.
     
  15. squidget

    squidget Junior Member

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    <table width="90%" cellspacing="1" cellpadding="0" border="0" align="center">
    <tr><td><span class="genmed"><b>mhpr262 wrote:</b></span></td></tr>
    <tr><td class="quote">Spinning up the projectile costs energy which can only come from the energy stored in the rubberbands. Whatever you think you can gain from getting your projectile to spin would be more than offset by the resulting reduction in ammo velocity. Fins are a much more effective and economical way of stabilizing the projectile in midflight.</td></tr>
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    <span class="postbody"><br><br>i realize spinning costs energy which also reduces distance <br>what i was wondering a round ball say a lead ball once fired will spin the idea i was thinking was if that spin could be somehow controlled like fetching on an arrow but because a ball would seriously loose its aerodynamic ability with something poking out grooves should create a similar effect.<br><br>a dimpled golf ball has a more controlled flight path than a smooth one so this is why i was thinking of grooving a ball projectile.<br>just thoughts <img src="http://illiweb.com/fa/i/smiles/icon_biggrin.png" alt="Very Happy" longdesc="1"></span>