calculating travel of a bullet

[BrokenBiker]

Mass (weight) doesn't matter ^^^

yeah i realised that after i typed it

 

[tflnemesis]

this one says 2.6 miles which is more like it

This calculator takes into account air resistance too. Without air resistance the bullet will travel a lot further.

 

[BrokenBiker]

i may have made an error with the 2.59 miles...worked it out again and its now 6.6 miles?

 

[BrokenBiker]

the original question has gone to pot now...people saying there is no waya .243 can travel further than 600 yards, some saying it will fly 30 miles, some saying there are target clubs that shoot .243 at 2 miles accurately etc...

 

[Tinbasherdan]

Know anyone in the military? I believe the gpmg can be used as essentially a small artillery piece in "map predicted mode" ie aiming up in the sky and predicting travel distance. Maybe some calc charts available

 

[chunkolini]

This hypothetical tosh has been on here before.

 

[ronan]

the original question has gone to pot now...people saying there is no waya .243 can travel further than 600 yards, some saying it will fly 30 miles, some saying there are target clubs that shoot .243 at 2 miles accurately etc...

There was a young fella playing football years ago in northern ireland and he suddenly fell dead to a gunshot wound, but no one heard the shot. Of course it was blamed on terrorists, spooks, silencers etc, all sorts of theories. The famous uk gunmaker, Robert Churchill, who was also a ballistics expert, worked out what had happened. Over a mile away a bloke was shooting magpies or crows that were roosting in a tall tree. Churchill worked out that the bullet had travelled through the high branches of the tree, had flown high into the air and came back down again with enough force to kill the young lad.

A million (or a billion) to one chance of the bullet coming back down and hitting someone, but it did happen.

A centrefire rifle round will fly a lot more than 600 yards.

http://www.startrader.co.uk/Action TV/guide60s/callgun.htm

 

[Jim Hayes]

There was a very unlucky guy who got killed under similar circumstances in the UK a few years back, got hit in the eye by a small bore rifle bullet whilst sat in his garden.
Apparently it could have come from anywhere within a few miles radius if fired at a high angle.
I can imagine a .243 might easily go for a couple of miles with enough force to kill, accurate might be another matter though!
It's seems rifle shooting for deer is now banned here on salisbury plain is now banned after a squaddie was killed by a stray round (not a military one) a few years back as well.

 

[CornishPete]

trying to remember the equations of motion! Seem to remember you work out how long the bullet stays in the air for then multiply by the speed?

 

[ronan]

The trouble is there are so many variable factors. Decrease in velocity, humidity, temperature, wind speed and direction. I suppose any answer you get is at best only going to be approximate.

 

[mcostello]

We had a country gentleman unload His black powder rifle by aiming at a neighbors girl 1/2 mile (inferial measurement), killed Her dead, went to trial, got 2 years for murder. A co-worker's Son was playing outside and a teen pointed a .22 rimfire rifle at Him from 1/4 mile (another inferial measurement), hit the Kid in the neck and paralysed Him. Dad was never the same. Kid confessed about 20 years later, still made the 11:00 news. No prosecution as the parents wanted it that way.

 

[optima21]

if would go about 4ft with me, the 45 degrees would be pointing to the ground instead of in the air.

 

[Screwdriver]

Flat level ground, no aerodynamics, I love these thought experiments. They don't really make much sense in the real world.

In those circumstances, if you had a laser sight, the bullet would hit the ground at exactly the same time as the light beam...

 

[Maker]

yes, im sure there a few on here that can...im hoping maybe maker pops in as he is an A level maths student i believe

I got 63 miles, I'll post again when I figure out what I did wrong.

 

[rockweasel]

I'm rusty at this sort of thing, but here's a starting point to get a feel for the sort of distance you're looking for:

1) If the bullet was fired horizontally out of the rifle then it fell from the muzzle's height at a rate of 9.81 m/s/s (g)
2) Height (H) of the muzzle is 6ft which is approx. 1.8m
3) Speed (V) of the bullet is approx. 1001 m/s (I converted from fps)

Time (T) the bullet spends in the air is Sqrt(2*H/g) which comes to 0.605s ish
Distance the bullet travels is V*T = 1001*0.605 = 605m

Now if you assume the same scenario but the muzzle pointed straight up at 90 degrees, then intuitively it will travel straight up and fall straight down. We're talking ideal circumstances, no wind etc. 0m

The answer to the original question then must factor in the angle the bullet is fired at. My toast is burning, so I must leave it there for now.

 

[rockweasel]

Vectors.

The distance the bullet travels is determined by the horizontal speed of the bullet and the time it spends in the air
The horizontal speed is determined by the angle of the muzzle to horizontal: V_horizontal=V*Cos(A)

{Sidebar:
Horizontal muzzle; A=0 degrees, Cos(0)=1
Vertical muzzle; A=90 degrees, Cos(90) = 0
}

The vertical speed is determined by the angle of the muzzle to horizontal: V_vertical=V*Sin(A)

Use the vertical speed to determine how long the bullet takes to come to a stop and drop back to the ground. Use that time and the horizontal component of speed to determine the distance travelled.

Now I've stewed my tea and the toast is cold

 

[rockweasel]

I should know this ****. When I left Uni I worked in the PDS (Post Design Services) department on a project called IFCS (Improved Fire Control System). It was a set of sensors/computer that took into account wind direction, temperature, barrel wear, atmospheric pressure, distance and the relative speeds and directions of the vehicle and it's target (two tanks as it happens) to tell the operator where to fire the shells.

I forgot I even did that

 

[norlander]

I think we were told the given range of the 7.62 mm fired from an SLR was 1,762 yards, but it could and would go further in some circumstances, safety distance might have been 2 or 3 miles (for ranges), I forget.
None of us bothered with that stuff, battle range was 300 metres max effective range 600 metres.Group fire could be 800metres
I think its muzzle velcocity was 2,700 fps
I think that 1,762 yards (if I recalled it right) might have been a mean distance from bench fired weapons

I found its best to be more concerned how near bullets are coming than how far they will go meself though.

 

[BrokenBiker]

I got 63 miles, I'll post again when I figure out what I did wrong.

So did I first, as did some of the calculators...I then got 2.59 and 6.6...

 

[BrokenBiker]

I have a simple way to figure it out...I e got a gun and ammo...just no where big enough to safely attempt it lol