I was curious to see which was the longest recorded sniper kill and stumbled upon Craig Harrison. He was serving in Afghanistan and killed a Taliban machine gun team from 2,475 meters, or 1.5 miles away. According to a post, it took around 6 seconds to hit his targets. However, the [weapon](https://en.wikipedia.org/wiki/Accuracy_International_AWM) he was using (L115A3) has a muzzle velocity of 936 meters per second. Using simple math, shouldn’t it have taken only 2.6 seconds to reach his target? Harrison himself claims that he had the perfect conditions with clear weather and no wind. Given all this information, what took so long for the bullet to hit? Was it because of elevation or some does my ape brain not comprehend this question?
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You know how a car slows down when you get off the gas? Or if you bicycle and stop pedalling – does the bicycle continue travelling at the same speed? In real life there are things like friction and drag, bullets slow down the further it travels.
The very sneaky mistake you made is that you assumed muzzle velocity was a static measure of the speed of the bullet. In reality, air resistances is perpetually draining velocity from the listed muzzle velocity the instant it is fired. It was 936 m/s at the muzzle, and when it hit him it was going MUCH slower.
Air resistance. The muzzle velocity wouldn’t be constant over very long distances as the projectile is passing through air which slows it down.
At short distances this would be negligible but at longer distances it would become more apparent.
[This wiki article explains it in detail](http://en.wikipedia.org/wiki/External_ballistics)
> “The deceleration due to drag that a projectile with mass m, velocity v, and diameter d will experience is proportional to 1/BC, 1/m, v² and d²”
You are missing air resistance.
>muzzle velocity of 936 meters per second
That’s the velocity when the bullet leaves the muzzle. After that it keeps slowing down due to air resistance.
If you factor in air resistance, you can still determine travel time, but because air resistance is itself dependent on velocity, it’s going to be related in a slightly more complicated way to distance, and muzzle velocity.
Also air resistance would vary slightly based on atmospheric conditions (humidity, pressure etc.). So you still might not get a perfectly uniform time to target.
You can find more details here https://en.wikipedia.org/wiki/Drag_%28physics%29?wprov=sfla1
In addition to the point everyone else has made about air resistance slowing the bullet, a very long range rifle shot doesn’t travel in a straight line. The rifle may have been 2,475 meters from the target, but the bullet travels in a parabolic arc after it leaves the muzzle, and the distance it travels upwards and then back downwards on the way to the target represents a substantial increase in the total distance it needs to go and therefore the time it spends on it’s journey.
Okay this is cool. Now somebody please do the math. How far could the bullet possibly travel in these perfect conditions. And is it actually possible to fire the bullet far enough that it could slow down so much that it could actually hit the target but not traveling fast enough to cause damage. I’m thinking it’s a trillion in one shot but, is it actually possible with the curvature of the earth and even slightly different elevations?
Bullets have forces on them while in flight, mainly air resistance and gravity.
So you start out at 3,070 fps, .338 Lapua, I’ll guess 270 grain (bullet weight) and consult a ballistics calculator. Because of the aerodynamic drag, you’re going to be down to about 2,000 fps at 1,000 yards, and under 1,200 fps at 2,000 yards. It’s slowing down the whole time, so it will take much longer.
And then you have gravity. Gravity is going to make that bullet fall over 100 feet over 2,000 yards, so you’re going to shoot at a fairly high angle so the bullet can fly in a high arc up over and down to its target. So the bullet didn’t travel only 1.5 miles, it traveled in a big arc over 1.5 miles, meaning its path taken was over 1.5 miles.
Because this:
>muzzle velocity of 936 meters per second
doesn’t mean the bullet travels that speed the whole way. It only starts that fast.
The math isn’t exactly *simple*. Air resistance means the bullet starts decelerating the instant it’s no longer being accelerated by the gas expansion from the powder burning.
Bullets slow down as they travel through the air, the muzzle velocity is measured right as the bullet leaves the muzzle, and should be the fastest the bullet is ever traveling. If fired in a perfect vacuum, the bullet should maintain constant velocity, but since there is air resistance, it will continuously slow down while in flight.
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