Sitting in the car on the a1 with some crows flying alongside at the same speed. If one were to shoot at said crows or indeed any object travelling at the same speed. Would you give the same amount of lead in front/more/less? Than if it were at the same distance and gun was static.

More in front methinks – higher relative wind speed?

No, because the object is not moving relative to you. It’s the same as shooting at still target, you just aim straight at it.

Its only when the object is travelling at a different speed to you that you need to compensate.

*edit, Just seen Woody’s answer. I forgot to take into account the bullet’s side ways velocity will reduce due to drag.

So I would aim slightly in front but not as much as if I were static and object was moving.

More in front methinks – higher relative wind speed?

Yep, that’s what I’d have thought. If you were driving in a vacuum with no gravity you’d have bigger problems than crows aim straight at them. But you’re not so you’ll have to adjust to compensate for wind speed and gravity.

Jairaj has it on an airless motorway but in the event you’d have to aim slightly ahead to account for air resistance – effectively wind-shear.

edit. See their edit.

Less, because part of the lead is because even in a vacuum if you shoot straight at the bird, by the time the shot reaches where the bird was it will no longer be there. If you’re in a moving car, the shot will have forwards momentum, so will go to where the bird is (in a vacuum).

The relative wind speed is the same – the bullet is travelling at the same speed as if you were standing still and simply giving the bullet more lead. So some lead due to air resistance, but not as much.

Shooting a passing bird from a standing position you need to aim ahead so as to give the bullet time to arrive where the bird will be.

But shooting from a position moving at the same speed as the bird you only need to allow for wind resistance to forward motion so I suspect you wouldn’t need to aim ahead very much, especially if the gun had a high muzzle velocity.

If you were in a vacuum with no air resistance you could simply aim and hit the bird no matter how fast you were both travelling as the wind component would be irrelevant.

More importantly what size bullet would you use! 😉

Flying alongside? How close?

If you calculate as vectors relative to a fixed point, say the point on the ground that you were when the gun was fired; the projectile (you don’t say if it is an airgun, a shotgun, or a rifle) would have a vector towards the crow due to the projecting mechanism, plus a sideways vector due to the car.

So the projectile would travel sideways at the same rate as the car. That is, until the effect of air resistance has a material effect, which will slow its sideways motion until in the end it only retains its forward component. (in fact, there’s also a downwards component but let’s not overcomplicate)

If the crow is very close it’ll make no odds, aim straight at it. If it’s a long way away, you need to lead by enough to compensate for the effect of air resistance on the projectile, but this will be less than you’d need to lead by if you were stationary.

Whichever, it’d be an easier shot to swing in behind it, stand out of the sunroof and shoot it up the arse.

imagine you have a 70mph side wind and rephrase the question.

😉

Whichever, it’d be an easier shot to swing in behind it, stand out of the sunroof and shoot it up the arse.

Plus you could catch it as it drops out of the sky.

Well that clears that up.

Now if it were travelling in the opposite direction at the same speed as I was. Say its a vehicle in opposite carriage way both doing 70. How would on calculate the amount of lead?

Double what you’d normally use, I’d hazard, plus a bit more for the aforementioned 70mph cross wind.

imagine you have a 70mph side wind and rephrase the question.

not that I’m in the habit of shooting avian friends from moving automobiles, obviously!!

AA -12 Automatic shotgun, fin stabilised mini grenades, air burst. Problem solved.

Hang on, are we helping plan a drive by here?

Hang on, are we helping plan a drive by here?

Shooting at crows, it’s more likely to be a murder.

Shooting at crows, it’s more likely to be a murder.

Cougar – Moderator
Hang on, are we helping plan a drive by here?
Shooting at crows, it’s more likely to be a murder.

Badum, tish!
Cougar is today’s winner of the Internet. 😆

If you were standing and the bird were in a tree, you’re both still moving through space at the same speed – rather quickly too. So it proves that you would not have to lead if it weren’t for air resitance.

AA -12 Automatic shotgun, fin stabilised mini grenades, air burst. Problem solved.

I say we take off and nuke the entire site from orbit. It’s the only way to be sure.

Not quite. Air resistance acts opposite to the direction of travel of the projectile – it slows the “forward” as well as the “sideways” motion in direct proportion to the speed of motion in each of those directions – it won’t ever cause it to change direction. So it never gets to a point where its motion only has a “forward” component.

<warning extremely geeky maths stuff ahead – please don’t argue with it if you don’t understand the concept of different reference frames!>
At least this is the case if you use the reference frame of the earth – if you use the moving car as a reference frame, which is reasonable in order to simplify things, then the projectile does follow a curved path due to air resistance, hence the need to still have some lead.

It does depend on wind speed and direction. If there was a tail wind that matched the speed of the car/crow then point straight at target. If the relative windspeed was less in the direction of travel aim in front. If the windspeed was greater (traffic slow in a gale), aim behind and the wind will bend your shot to the target. Although this third option would mean that the crow is flying backwards relative to the air around it.

M1llh0use – Member
imagine you have a 70mph side wind and rephrase the question.

That’s a speedy crow.

The range is another factor.

Should you not just hit the brakes and take them from behind?

Use SABOT round and its academic how fast you or the crow is travelling.. the fastest moving object in the world will have that crow dead at a speed around 1900m/sec.

In truth, you probably want to use HESH, slower ( 700m/s) but a bigger bang! 🙂

Mythbusters did something similar with wingwalkers playing tennis the other day.

..Chally could employ a banned shotgun round to deal with a few wing walkers!

If you were in a vacuum with no air resistance you could simply aim and hit the bird no matter how fast you were both travelling as the wind component would be irrelevant.

Well it wouldn’t be able to fly in a vacuum so why not just walk up to it and wring it’s neck, save the cost of a bullet.

You will need to account for wind and the movement of the bird. If you speeds are matched so that your relative positions are constant then just the wind. It would be exactly like shooting a static target on a range. Afterall while shooting at a static target, both you and the target are hurtling through space orbiting the sun.

Well it wouldn’t be able to fly in a vacuum so why not just walk up to it and wring it’s neck, save the cost of a bullet.

Because in a vacuum it would already be asphyxiated.

Well it wouldn’t be able to fly in a vacuum so why not just walk up to it and wring it’s neck, save the cost of a bullet.

https://en.wikipedia.org/wiki/Chicken_gun

Because in a vacuum it would already be asphyxiated.

It might be wearing a space suit. Or scuba gear.

Very clever these crows…

Yeah, but you’d have to remove the space suit to wring its neck…

Not the bullet question but this Saudi cleric is still struggling with the ‘plane on a conveyor:

http://www.telegraph.co.uk/news/worldnews/middleeast/saudiarabia/11419428/Watch-Saudi-cleric-tells-students-Earth-does-not-rotate.html

To put another spin on it – if your bullet has a velocity of say 100 m/s and you were theoretically travelling backwards at 100 m/s, what would happen to the bullet? Would it just fall to the floor?

Yes, but it does that anyway. If you fired a gun and dropped a second bullet at the same time, they would both hit the ground at the same time. Presuming there isn’t some kind of aerodynamic flight effect from the spinning, which I’m not sure about.

So many veriables , temp , wind speed ,bullet weight , And to think I sold all my shooting gear 6 months ago to get back in to riding..

Anyways whats the crow done to warrant such a untimely demise , not broke a sacred oath my having a bit with a red head from T`other side o wall ? has he

Molgrips > That’s a brilliant answer, good work.