Less wind drift - heavier weight or more speed?

[tor47]

In my mind I imagine a pellet in flight encased inside a ball of turbulent air. The higher speed the pellet has, the bigger that ball around the pellet will be. When the wind blows, the ball act as a sail for the pellet. The wind catch the ball, which again push the pellet out of course. So at to high velocity the negative effect of a bigger ball outweigh the positive effect of higher speed. Going to slow, the ball will be small with little wind effect, but the the negative effect of the pellet spending to long time in flight, outweigh the positive effect of a small ball.

Probably not a scientific correct way of looking at it, but easy to understand

 

[Ezana4CE]

In my mind I imagine a pellet in flight encased inside a ball of turbulent air. The higher speed the pellet has, the bigger that ball around the pellet will be. When the wind blows, the ball act as a sail for the pellet. The wind catch the ball, which again push the pellet out of course. So at to high velocity the negative effect of a bigger ball outweigh the positive effect of higher speed. Going to slow, the ball will be small with little wind effect, but the the negative effect of the pellet spending to long time in flight, outweigh the positive effect of a small ball.

Probably not a scientific correct way of looking at it, but easy to understand

That is actually a lot simpler to conceptualize thinking in terms of balls and sails. 

 

[OldSpook]

Don't think of wind as being wind. At the exact time you fire, think of it as a fixed snapshot of a three dimensional pressure gradient (higher resistance on one side, lower resistance on the opposing side, and not in a linear fashion—it's always changing throughout the snapshot) that the projectile must pass through. All other things being equal, a projectile with a higher inertial mass will be less affected by this external pressure gradient than a projectile with a lower inertial mass, since the higher inertial mass allows it to be more resistant to changes in acceleration—in this case, the "side-to-side" forces of that 3D pressure gradient that the projectile is passing through.

No,,,,do think of it as wind and think of the side profile of the pellet as the surface against which the wind blows, While we commonly refer to ballistic coefficients, they are generated by the tip profile and the air around them whereas wind drift is generated by the side profile and the wind against it. There are some similarities of the two numbers because they partly are function of the mass of the pellet, or slug. however the side profiles are quite different for some equal weight projectiles and do also determine wind drift. You probaly could calculate a ballistic coefficient for a side winded drift , assuming that the wind force is acting similar to gravity

 

[Saltlake58]

OK, I ran the numbers through Chairgun and made an error that is interesting.

Compare .25 cal JSB 25.39 grain vs the .25 cal 33.95 grain pellets. Punched in the weight differences, but failed to change the BC. Chairgun treated both as exactly the same wind drift.

Corrected the BC on the two pellet types respectively, and yes, now there's a difference in wind drift.

I think that says if I have a 25 grain slug, it'll have less wind drift than a 34 grain pellet. In other words, the overall combination of components (weight, shape, drag and the rest) are more important than a single element like weight.

May not seem like much, but I learned a valuable lesson from this conversation.

Many thanks,

 

[AirShot]

Most of these test are shooting a light and a heavy pellet at same speed. I took the original question to mean if a light pellets goes 900 fps and the same gun shoots a heavy pellet at 780 fps, which pellet has less wind drift??

 

[Saltlake58]

Understand better now. If you assume that the different pellets put out the same energy at the muzzle, according to Chairgun, the 25.39 pellets shoot at 850, 33.95's shoot at 730 fps. Both now put out about 40 foot pounds at the muzzle.

25.39 drift in a 5 mph wind is 5.9 inches at the target

33.95 drift in a 5 mph wind is 5.1 inches at the target

Zero and target are 100 yards in this example.

So, according to Chairgun, the heavier pellet will buck the wind slightly better when speed is adjusted to make muzzle energy roughly equal.