17 HMR or 22 WMR

[joe-nwt]

Normally, I don't consult the ballistic charts. I simply hold from 0.1 to 1.0 gophers into the wind depending on the situation. Seems to work.

 

[Meroh]

To further complicate matters, within the Transonic range of 0.8-1 mach (~900-1125 fps), the coefficient of drag changes significantly for very small changes in velocity. Since drag is a considerable component of wind deflection, projectiles traveling through the Transonic range will experience greater wind deflection than those that do not.

With regards to velocity, faster = less wind deflection is not an absolute. Indeed, a slower, heavier projectile with a greater BC *can* (not always...) outperform a faster, lighter projectile with a lesser BC. For any given projectile of a constant weight and BC, there will be a crossover point wherein an increase in velocity does overcome the drag component (BC and weight), and faster will = less wind deflection from that point, for that bullet.

Exterior ballistics is not as simple as "wind pushes the bullet" (which, of course, it does not actually do), yet a thorough discussion of the topic would involve more scientific jargon than the casual shooter would care to indulge. As few of us here have PhD's in physics, such discourse would quickly cause one's eyes to glaze over in disinterest.

This statement I agree with; the heavier projectile has more inertia than does a lighter one, and therefore it will take longer for the wind to have an effect on it; but a 500 gr. bullet traveling 200 FPS slower than another identical bullet, will have more time for that crosswind to affect it. A 500 gr. bullet traveling the same speed as a 50 gr. bullet will be less affected by drift over 100 yards.

If we are comparing a bullet over a given distance that goes transonic to one that does not, is just adding another variable to the equation. Generally any bullet that drops from supersonic will be less accurate due to the stabalizing effects of the shock-wave catching up to it.

 

[Meroh]

This is incorrect. Your statement is contrary to what Bryan Litz wrote in his book “Applied Ballistics”

Wind deflection is a product of the difference of bullet flight time in a vacuum vs in air. Velocity does reduce wind deflection but not nearly as much as the BC of the bullet.

In a vacuum, not only is there no wind deflection; there is no wind drag; the only force acting on the bullet would be gravity; unless you were firing it sitting on the outside of the international space station. LOL

 

[coleman1495]

This statement I agree with; the heavier projectile has more inertia than does a lighter one, and therefore it will take longer for the wind to have an effect on it; but a 500 gr. bullet traveling 200 FPS slower than another identical bullet, will have more time for that crosswind to affect it. A 500 gr. bullet traveling the same speed as a 50 gr. bullet will be less affected by drift over 100 yards.

If we are comparing a bullet over a given distance that goes transonic to one that does not, is just adding another variable to the equation. Generally any bullet that drops from supersonic will be less accurate due to the stabalizing effects of the shock-wave catching up to it.

There is so much incorrect physics in this I wouldn’t know where to start.

Stop making stuff up and read a book about ballistics.

 

[coleman1495]

In a vacuum, not only is there no wind deflection; there is no wind drag; the only force acting on the bullet would be gravity; unless you were firing it sitting on the outside of the international space station. LOL

Wind deflection=time of flight in air-time of flight in vacuum X wind speed