I think wind drift is more proportional to the pellets BC. So a .22 RD Monster with a BC of 0.052 would drift half as much as a .177 Exact with a BC of 0.026
And that same .22 RD Monster would actually drift less than the .30 cal JSB 50.1 grain with a BC of 0.046. Makes you think doesn’t it?
https://hardairmagazine.com/ham-columns/the-external-ballistics-of-diabolo-pellets/
Thanks Centercut,
From what you shared to us and from what I found in wikipedia, I made some cut and paste that I thought would be interesting to note.
1.-
BCs can be used to accurately estimate the amount of drop a pellet takes at different ranges. That means the parabolic trajectory. 2.- In my experience, when pellet shooting, the amount of drop is really similar in diverse JSB pellets irrespective of the caliber if they fly at same speed (FPS). 3.- The main aspect that affects the accuracy at long range is wind factor: How much the pellet is afected by the wind. There could be a lot of mathematical BC calculations, but what we all have experienced is that a 100 yards wind factor is the key in a .177 air rifle.
4.- The pellet has a weight and the wind has a weight. There are components of interaction among those two forces: The caliber of the pellet and the lenght of the pellet (volume) that is supported by the weigh of the pellet. The weight of the wind should be consider a constant.
Next I include some cut and paste.
Quote:
"Because the BC changes with the pellet’s velocity, there is actually no single Ballistic Coefficient for any airgun pellet! And due to the variability inherent in each individual airgun pellet, the Ballistic Coefficient of two “identical” pellets can also be different! In spite of all these issues, knowing a typical Ballistic Coefficient value for the pellets you are shooting is highly beneficial for calculating their trajectory. In conjunction with a software program such as Chairgun, BCs can be used to accurately estimate the amount of drop a pellet takes at different ranges. You need this for accurate shooting!" "Methods and the standard projectile[edit] Many militaries up until the 1860s used calculus to compute the projectile trajectory. The numerical computations necessary to calculate just a single trajectory was lengthy, tedious and done by hand. So, investigations to develop a theoretical drag model began. The investigations led to a major simplification in the experimental treatment of drag. This was the concept of a "standard projectile". The ballistic tables are made up for a factitious projectile being defined as: "a factitious weight and with a specific shape and specific dimensions in a ratio of calibers." This simplifies calculation for the ballistic coefficient of a standard model projectile, which could mathematically move through the standard atmosphere with the same ability as any actual projectile could move through the actual atmosphere.[31][32][10]" Wind Drift When you shoot in a crosswind, the pellet drifts sideways, causing your POI to be downwind of your POA. The largest factor governing the magnitude of this drift is the BC. There are many misconceptions about wind drift, the biggest being that “time to target” is the key. That is NOT the case. The wind drift is proportional to the DIFFERENCE in the actual time of flight, compared to what it would be in a vacuum. This is called the “lag time”. This is a difficult thing to wrap your brain around, and even harder to explain without involved mathematics, so I will leave to you Google it if you don’t believe me. However, it is a fact that we have to deal with when considering the external ballistics of diabolo pellets. Since the lag time is the key, then how fast the pellet slows down (mostly governed by the BC) is the key. The chart below show how much the wind drift changes as we change the BC. " I would disagree in the following statement:
"The largest factor governing the magnitude of this drift is the BC." If we agree that
BCs can be used to accurately estimate the amount of drop a pellet takes at different ranges, that means that BC is meassuring the interaction with one force: gravity. Wind drift is a diverse force that is not vertical but mainly horizontal to the ground Then I would lke to go back to my initial comment in this thread: "Let´s try to meassure eficienciy vs. wind on each pellet".
For sure there has to be some factors to take into account:
Weight of the pellet and surface in contact with wind, ant time of suffering the efect of the wind force before getting to target.
The quickest loss of acceleration of a pellet, the more time in contact with wind force before getting to target.
Loss of acceleration is related with weight and speed. If the speed is a constant in all calibers, then the weigh and volume is what determines the interaction with the cross force of the wind.
