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Aerodynamic Jump- video

I believe? In a 90deg. L or R wind, there is a low PSI area generated above or below the spinning projectile? (Depending on R twist or L twist rifling w/regards to wind direction) This effect is more pronounced in a standard rifled barrel vs. say a polygonal or smooth twist barrel, also in my mind I think L-wind low, R-wind hi. Not sure about my low psi theory being accurate? Been awhile since my last physics class... but very nicely done well explained and demonstrated!
 
Great explanation with the video. This would have definitely helped me when I was trying to wrap my head around it a few years ago.

I like to use my charts also, you would think this would be ingrained in my brain by now ;-)

1558784386_14662678565ce929820e56b1.88845919_windchart bullet displacement.jpg


1558784402_12427273285ce92992135fe5.38307555_windchart poa.jpg

 
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I believe? In a 90deg. L or R wind, there is a low PSI area generated above or below the spinning projectile? (Depending on R twist or L twist rifling) This effect is more pronounced in a standard rifled barrel vs. say a polygonal or smooth twist barrel, also in my mind I think L-wind low, R-wind hi. Not sure about my low psi theory being accurate? Been awhile since my last physics class... but very nicely done well explained and demonstrated!

For beginners you’re saying Polygonal & Smooth Twist are more aerodynamic due to the shallow or almost non existent fin engraved by means of twist be it traditional rifling, a poly, or FX’s ingenious twisting of exterior muzzle of barrel matched with the perfect tapered choke for friction & sizing pellets. Yes?
 
JamesD. Some what? “YES” to first comment “NO” to second! :To pcparmy please excuse me! I don’t want to take this topic/thread off it’s intended course... please keep vids coming! Can’t wait for the one on mirage/boil, and how the wind can actually help in this case! “So you AIM where the bull actually is not where you think it is... waiting for the boil to “SNAP”
 
Kudos to you "Doc". Wishing you & your loved one's a happy Memorial Day weekend.

Outstanding presentation & excellent analogy utilized in the explanation, understanding and application of combatting aerodynamic jump. Another exemplary example of your overflowing generosity to all who enjoy the sport of shooting. Your shooting skills speak for themselves NO words necessary.

CampFussell - Those wind charts are simply wonderful & most beneficial to all who are in need. Thank you for sharing them with all of us.
 

pcparmy

Member
Mar 27, 2019
351
16
NY
    Thanks guys. Good contributions as well!

    those charts are timeless, but often forgotten on the range. “Dang zero is off again!” “‘Maybe its because its a little warmer today”.

    “Did i bump my scope?”



    These questions plagued me for a long time when I was good at squeezing but nothing else. They still do sometimes. Just another piece of the wonderfully complicated puzzle that shooting is. Thats why its fun!



    radio - you are always so kind. Thanks for the support and words!



    also the “shooting tables” are really just very sturdy synthetic tv dinner trays. As in, if you ate dinner sitting on the couch, its what you would use. They are light, portable, tough “, and cheap!
     
    Nov 25, 2017
    589
    12
    mo
      At first this was quite thought provoking, but then my Junk Science detector went off and pulled my brain back into the real world.

      The rate of spin would have to be outrageous to have a noticeable effect. For example: However many times a smooth textured .22" pellet can be rolled across a flat surface that is 12" wide ..... that's how much rotation per 1 foot of travel it would take to raise POI .220" every 80 feet (or 26.6 yards) against gravity even if the pellet weight was as light as 11gr.

      So since barrel rifling imparts only a sparse fraction of that kinda spin, I can't fathom even a 40mph crosswind doing anything other than shoving a pellet sideways and down, regardless of right/left spin at a rate of less than 2 rotations per 1' of travel 

      If your POI climbs against gravity it is because the lighter end of the pellet is being blown sideways, and possibly down, changing the aerodynamic direction it is traveling. It is NOT because the pellet is "rolling up (or down) the wall of wind".

      😄
       
      G

      Guest

      Guest
        As I've not watched the video I can't comment on the science. I can give anecdotal evidence from Many matches shot in nearly every condition not in my back yard. A l-r or r-l wind will move your pellet up or down depending on it spin. What I feel most people are seeing is poor form from poor trigger pull to not repeating thier hold. Another and often never looked at culprit is a horizontal swirling wind( dust devil on its side). I've watched my pellets hit low and high on the same target while my windicator shows the same wind direction. Take the info as you will and please remeber to test for yourself Then come back to argue😘
         

        pcparmy

        Member
        Mar 27, 2019
        351
        16
        NY
          Fishinwrench,

          It’s possible you stopped watching the very moment you disagreed with my analogy, but I do clearly state in the video that -

          “This is not the correct scientific explanation,” just a way for people to think of it so it makes sense.

          Thats why the video was titled “aerodynamic jump- SIMPLIFIED”

          Hopefully the correct implications stuck in peoples minds, if the real science behind it is desired a much more in depth video is in order.






           

          pcparmy

          Member
          Mar 27, 2019
          351
          16
          NY
            John,

            While i think you are right many folks struggle with holding the same each time, those that do not will absolutely see the effect that you have noticed. This isnt a “might happen thing”, this absolutely happens with every shot, its just how much based on distance/time of flight and wind intensity.



            I always found myself frustrated on windy days trying to gather dope. Once i understood jump, it all became much clearer. Im hoping that the folks shooting “way out there” that might have missed this, now can understand whats happening.



            At 150 yards an moa and a half is frustratingly close, and easily dismissed as a shooter or gun error. Especially in the crazy wind it take to generate a 1.5 moa change. If you feel the shot is good though, analyse your trigger pulls on video, and your gun is performing, its nice to be able to explain the shift.

            Not scientificaly though of course, lolol
             
            I love these topics so I’m going to keep jumping in here! There are so many environmental & atmospheric variables at play when it comes to accurate shooting with these slow fps airguns it’s unbelievable that we have taken shooting ( distance & 25m competition) as far as we have impressive! And I agree John more than once I’ve had stratified winds reek havoc with trying to hit the x-ring? Or vortexes generated off berms & structures? all things that leave you scratching your head after the match? ( that’s why I laugh when someone says I’m picking a bench or I got lucky my bench is by the BERM... ok have fun with that I think to myself 😳
             

            pcparmy

            Member
            Mar 27, 2019
            351
            16
            NY
              Hahah so true mojo



              I love those wide open fields for woodchucks. Buildings are our current nemisis. Swirling and dropping winds on top of us while trying to shoot pigeons . Ill try factor in what i feel and see, and be rewarded with a complete surprise when my slug lands lol. One of Our favorite farms is a mess of tall buildings and the wind is completely variable at all times