Pellets don't rise!

Discussion in 'General Airgun Chat' started by KeithW, Nov 8, 2019.

  1. Leadedd

    Leadedd New Member

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    I'd say pellets do rise slightly above the theoretical horizontal due to muzzle flip and the way barrel porting is done infavour of the vertical. Saying that I don't really care enough to argue about it.
     
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  2. Dan Smith

    Dan Smith Active Member

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    They do rise cos you’re pointing up a bit init!
     
  3. KeithW

    KeithW Barn door? Where?

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    Erm ... I clearly said "launched horizontally".

    As others have pointed out, if you angle the launch upwards the projectile will initially fly upwards - no argument from me there!
     
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  4. KeithW

    KeithW Barn door? Where?

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    Are you still pointing up a bit if the target it below the level of your barrel?
     
  5. Stevo86

    Stevo86 Member

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    Enjoyed the read and the responses opened my eyes a little more
     
  6. KeithW

    KeithW Barn door? Where?

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    Me too! :D
     
  7. KeithW

    KeithW Barn door? Where?

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    Indeed. Artillery gun setters used to use gun tables to calculate elevation. However at "point blank range" no adjustment to elevation was necessary because the power of the gun meant the shell only dropped a negligible amount over the short distance - ie, they "just poked it"
     
  8. KeithW

    KeithW Barn door? Where?

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  9. KeithW

    KeithW Barn door? Where?

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    At the moment of flip the barrel end jumps up, thus launching the pellet upwards
     
  10. Leadedd

    Leadedd New Member

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    We are talking about gun/ barrel harmonics here but a test that would settle all arguments (if anyone was dedicated/ borderline mental) would be to set a gun up vertically and the point of impact should be exactly inline with the barrel say @5m inside no wind. Anything continually outside of this would be proof especially if the pellets deflection matched the barrels high point or barrel deflection angle.
     
  11. Cooper_dan

    Cooper_dan Well-Known Member

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    But its i hell of a lot easier to tell new shooters they go up before they come down.
    That way they can be knocking over 8 and 45 yard targets and have a bit of an idea why they are aiming where i tell them to.
     
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  12. RICHARD WOODS

    RICHARD WOODS Active Member

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    If youve ever wondered how far your pellet actually drops over a given distance, simply turn the gun 90 degrees and shoot it. Obviously youd need your windage sorted first. You should find that it goes the same amount left or right as it does downwards. Its actually quite a big drop even at say 25yds.
     
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  13. dave croucher

    dave croucher FT, the sport where simple becomes complicated

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    Did that once, shot the bloke next to me on plinking range
     
  14. Ballisticboy

    Ballisticboy Active Member

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    Erm actually a pellet can rise for a short distance even if fired horrizontally. It is all down to the initial yawing rate and what direction it is in. You do not need wings to produce lift, bodies can do it perfectly well without any wings (the Harrier aircraft could produce three times its own weight from the body alone which was lucky as the wings were not very big), it is just that wings are more efficient in terms of the lift drag ratio. If a pellet yaws upwards on leaving the barrel then it can rise above the barrel line of fire before falling back down below it. For gun launched projectiles the movement away from the normal trajectory line is known as heave and swerve.
    Having said that I don't believe for one minute that anyone who wrote it in a magazine would know that, except Jim of course. ;)

    Perhaps I should add that any rise above the barrel line will only be very small and will be unlikely to occur on every pellet unless there is a barrel problem producing a bias in the pellet flight.
     
    Last edited: Nov 9, 2019
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  15. KeithW

    KeithW Barn door? Where?

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    I appreciate the clarification (and the proper science!)
     
  16. Thirteen

    Thirteen New Member

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  17. Ballisticboy

    Ballisticboy Active Member

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    The pictures show a much simplified perfectly behaved pellet trajectory with no yaw produced heave and swerve which you will always get no matter how good your gun and pellet. The pictures are fine for the purpose of the article which contains them but are in no way representative of the true detailed behaviour of a pellet in real life and were not meant to be. Chairgun is also unable to show a detailed trajectory being a point mass model when a full six degree of freedom model is needed to show such complex behaviour.
     
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  18. Thirteen

    Thirteen New Member

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    I dont use chairgun dude, I acknowledge you are coming at this from a strictly technical point of view, but we are shooting off our knee predominately on uneven ground mostly, and in wind, rain.uphill, downhill and canting, its a basic principle with too many environmental/human variables to compute, and in the grand scheme of things .....does it matter, when you are tuning small arms projectiles it is more relevant but with very limited improvements that can be made to a pellet and recoverable data to improve hit ratio success..... does it matter
     
  19. Ballisticboy

    Ballisticboy Active Member

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    Not really talking about different variables or if it matters or not in the overall accuracy of the system, just pointing out that the diagrams referred to were not meant to show a detailed trajectory of a pellet and could not show detail behaviour being too simplistic and not meant to be for such purposes. Therefore saying that they are a simple accurate description of pellet flight is not true as they are not accurate and do not answer the OP.
    As for saying only very limited improvements can be made to a pellet that is like saying modern cars are no improvement on a Model T ford made to tighter tolerances.
     
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  20. Thirteen

    Thirteen New Member

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    Don't really agree with some of your points buddy but respect your opinions
     
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