Where do the bullets go?

[Tony C]

I'm quite likely making this up but I do seem to remember watching a programme (could it have been a show like Mythbusters or similar?) which stated that by the time a round reached the ground from height, its velocity had diminished enough to prevent it from being fatal!

Not saying it wouldn't hurt and if true, would imagine that the spent casing would equally be non-fatal!

[Stephan Wilkinson]

A falling object rather quickly reaches its terminal velocity, whether it's a penny or a brick, and though that velocity is certainly speedy, it isn't incredibly high. For an object dropped out of a tall building, it has reached TV by the time it has fallen 15 stories. And yes, thicker air at lower altitudes would diminish it.

[airnutz]

It's to my understanding, a streamlined object like a .50 casing...assuming the base and primer end would impact first..would reach a terminal velocity of about 200mph. Sounds like that would be ample to penetrate an un-helmeted head. What say our resident engineers? What does a .50 casing weigh..about .25 pound? How many psi of force would the impact point receive?

EDIT
I started typing before Steve posted, but I'll leave the post and take my lumps when the engineers show up..

[Dan K]

It's to my understanding, a streamlined object like a .50 casing...assuming the base and primer end would impact first..would reach a terminal velocity of about 200mph. Sounds like that would be ample to penetrate an un-helmeted head. What say our resident engineers? What does a .50 casing weigh..about .25 pound? How many psi of force would the impact point receive?

EDIT
I started typing before Steve posted, but I'll leave the post and take my lumps when the engineers show up..

Studies on .30 cal and .50 cal ballistics were done by Julian Hatcher back in the 1930s. Hatcher calculated terminal velocity for .30 cal at about 300 feet per second; .50 cal is around 500 fps (due to its greater mass).

About the only remaining variable is whether the bullet is still spinning (doubtful) or tumbling.

[shrike]

It's to my understanding, a streamlined object like a .50 casing...assuming the base and primer end would impact first..would reach a terminal velocity of about 200mph. Sounds like that would be ample to penetrate an un-helmeted head. What say our resident engineers? What does a .50 casing weigh..about .25 pound? How many psi of force would the impact point receive?

EDIT
I started typing before Steve posted, but I'll leave the post and take my lumps when the engineers show up..

Studies on .30 cal and .50 cal ballistics were done by Julian Hatcher back in the 1930s. Hatcher calculated terminal velocity for .30 cal at about 300 feet per second; .50 cal is around 500 fps (due to its greater mass).

About the only remaining variable is whether the bullet is still spinning (doubtful) or tumbling.

Lazy Dog - air dropped kinetic munitions, were clocked at 700fps. Even working with Hatcher's numbers (and if ever there was 'expert testimony' it's Hatcher), that gives us roughly the same velocity as .45ACP at 100m, but more than 3 times the mass for a .50 bullet. (750gr(48.6g) vs 230gr(15g))

A spent .50 cal casing is approximately 850gr (.125lb or 55gram). It's terminal velocity should be lower because of the flat base (it'll shuttlecock base down) but someone else will have to test just what it is. It should still be carrying enough energy to be thoroughly unpleasant to be hit with.

[Dan K]

Lazy Dog - air dropped kinetic munitions, were clocked at 700fps. Even working with Hatcher's numbers (and if ever there was 'expert testimony' it's Hatcher), that gives us roughly the same velocity as .45ACP at 100m, but more than 3 times the mass for a .50 bullet. (750gr(48.6g) vs 230gr(15g))

A spent .50 cal casing is approximately 850gr (.125lb or 55gram). It's terminal velocity should be lower because of the flat base (it'll shuttlecock base down) but someone else will have to test just what it is. It should still be carrying enough energy to be thoroughly unpleasant to be hit with.

Make that "sleep-deprived dog"...I hadn't even realized the thread had turned to falling casings!

Mea maxima culpa

[Michel Lemieux]

Make that "sleep-deprived dog"...I hadn't even realized the thread had turned to falling casings!

Mea maxima culpa

Still a very interesting spin to a basic question nobody ever figured to ask......

I like it....

Merry X-mas all.

My bet is independently of terminal velocity......it is not intentionally aimed. Thus lowering real risks of recorded events.

Cheers.

[A26 Special K]

Back to where bullets fall, consider that many of the gunnery ranges in Az especially those used for aerial gunner practice like Kingman and over in Nevada around Las Vegas quite often turn up spent bullets on the desert floor especially after some rain erodes the topsoil just a bit.
On another note, recently ran across an environmental study on the clearing of hazardous materials from the shotgun range at the Dalhart Army Air Force Base in the Tx Panhandle. While most of the WW2 period was spent in training bomber crews like the B-17, B-24, A-26 and B-29, there were a few fighter pilots trained also. In fact. Col Tibbets pulled the core unit for his 509th (Atomic Bomb unit) from Dalhart on the recommendation of his old friend, General Frank Armstrong who was 3/4’s of the role model for the character of General Frank Savage in the book and movie Twelve O’clock High. Tibbets was the other 1/4 by the way. Anyway, lead from the shotgun practice ranges were only part of the problem. The binding material in the clay targets turned out be a very nasty chemical. Who knew....