What happened to bullets that missed in Aerial Battles?

[gruad]

Assume a 30mm cannon mine shell fired at 25,000 feet.

I assume the bullet of a missed shot would slow horizontally running a parabola as it dropped out of the sky. The bullet would hit the ground at terminal velocity.

Would that be sufficient speed to:

1. Kill or injure someone the shell fell on.

2. Trigger the explosive in the shell.

Did people take cover from falling ammo?

Thanks to anyone who knows the answers.

 

[pbehn]

Assume a 30mm cannon mine shell fired at 25,000 feet.

I assume the bullet of a missed shot would slow horizontally running a parabola as it dropped out of the sky. The bullet would hit the ground at terminal velocity.

Would that be sufficient speed to:

1. Kill or injure someone the shell fell on.

2. Trigger the explosive in the shell.

Did people take cover from falling ammo?

Thanks to anyone who knows the answers.

I don't know about 30mm shells. I do know that stories of civilians being straffed by American fighters were almost all put down to an air to air combat close by. In the Battle of Britain residents could hear and sometimes felt rifle calibre rounds and casings falling, a squadron of Hurricanes fighting with 109s around some bombers must have dropped thousands of rounds in a comparatively small space, children used to collect them, house drainage channels were good places to look.

 

[Admiral Beez]

Assume a 30mm cannon mine shell fired at 25,000 feet.

I assume the bullet of a missed shot would slow horizontally running a parabola as it dropped out of the sky. The bullet would hit the ground at terminal velocity.

Would that be sufficient speed to:

1. Kill or injure someone the shell fell on.

2. Trigger the explosive in the shell.

Did people take cover from falling ammo?

Thanks to anyone who knows the answers.

I'll have to defer to those with greater numeracy than I, but AIUI once its momentum is exhausted it will fall at the same rate as anything else; gravity (9.8 meters per sec or 22 mph) minus air resistance. A spent bullet or cannon shell would tumble about in the wind, likely slowing down to non lethal speed.

 

[yosimitesam]

I'll have to defer to those with greater numeracy than I, but AIUI once its momentum is exhausted it will fall at the same rate as anything else; gravity (9.8 meters per sec or 22 mph) minus air resistance. A spent bullet or cannon shell would tumble about in the wind, likely slowing down to non lethal speed.

It will accelerate toward the earth with increasing speed up to the object's terminal velocity, at 9.8m/s/s (9.8 meters per second, per second) or it's velocity will increase 9.8m/s for each second is falls. After 1 second it will be falling 9.8m/s and after 2 seconds it will be falling 19.6m/s and after 3 seconds it will be falling 29.4 m/s, and so on. The 'algebra' of the m/s/s is equivalent to m/s^2 (meters per second squared.) The actual velocity will be less than this due to air resistance (friction.) The friction force is proportional to the velocity^2 (squared) and so increases until it equals mass x 9.8m/s/s and the object no longer accelerates but is falling with it's terminal velocity. The friction force proportionality (constant multiplier) depends on the object's geometry, i.e. a tumbling bullet will have a lower terminal velocity (higher friction constant) than a nose-down-and-spinning one. This is an oversimplification of the ballistics of falling stuff, but close enough, I hope.

During the German air assault on Britain, people didn't go outside (during air raids) without their tin hats because a 1/4-oz dense object falling from great height ( having a low friction constant) could be lethal. Flak shell fragments, spent brass cartridge cases of all sizes, and expended 'bullets' clattered like rain on a roof sometimes, according to eyewitness accounts.

 

[GrauGeist]

One of my posts from this thread:
What goes up must come down: the hidden cost of antiaircraft artillery

Plenty of cases of people on the ground being hurt or killed by AA shrapnel or stray bullets from above.

One such case was a Dutch girl killed by stray bullets from a Polish RAF flight as they were strafing boats in the canal, the bullet(s) having traveled some distance.

Another instance, was the "Battle of Los Angeles", where the schrapnel from the AA caused minimal damage to property but resulted in 5 deaths.

We had a good thread on this subject several years back, though I can't find it at the moment.

 

[Thumpalumpacus]

Sure, they could kill or injure people. I don't know if any explosive shell would be set off; I don't know those sorts of technical details.

 

[GregP]

We have a perfect record with bullets and airplanes.

We have never left one up there yet. They all hit the ground sometime. In the case of bullets, they will not continue to accelerate once they reach terminal velocity, but will retain some horizontal velocity as well as increasing vertical velocity until terminal velocity is reached. Then they fall with slowly-decreasing horizontal velocity and slowly-increasing vertical velocity until they hit the ground.

Hopefully, the airplanes hit the ground with low vertical velocity and survive to be flown again. Sometimes not.

 

[ThomasP]

There was enough of a problem with explosive rounds hitting the ground that the Germans started adding a self-destruct (mechanism? powder train?) to their 20mm and 30mm aircraft cannon shells. I think this was begun in late-1943, but I have never been able to find precise data for when this started. The self-destruct is mentioned in several of the British ordnance pamphlets.

 

[A.G. Williams]

Yes, the German designation for a self-destruct feature was Zerleger. There were two ways of achieving this: tracer projectiles could have a link between the tracer and HE compartments so the HE exploded on tracer burn-out; or it could be built-in to the function of the fuze.

It is quite common for SD to feature in AA cannon ammunition as well (land and naval).

The terminal velocity of a .30 cal bullet can vary from 180 fps (tumbling) to 450 fps (falling point-first). The first case would cause injury, the second would probably be lethal.

 

[rednev]

between 2.46 and 3.32

 

[MIflyer]

Most of the bullets that missed went into the Phantom Zone. A smaller percentage went into the Twilight Zone. The rest....?

Quote from the BoB:

Butler: "We are having crumpets for tea, sir. Oh, and they are machine gunning the rear garden."

 

[bdefen]

My brother, USAF Retired, served at the palace in Baghdad earlier this century. Whenever outdoors, they were ordered to wear their kevlar helmets and body armor. Not only were there the hazards from air or ground combat, or insurgents, but also from shots fired into the air during celebrations by the locals. One guy my brother knew of did get hit on the head by a falling round. The kevlar helmet protected him, but the impact knocked him down. So was it a fully "spent", gravity powered round, or a still active, ballistic projectile? Who knows? Get under cover!

 

[special ed]

In WW1 flechettes (Spelling ?) were developed to drop on German trenches. They were miniature steel bomb shaped solid missiles with small fins said to be able to penetrate steel helmets when dropped from the proper height. I used to buy them in the 1960s from a military surplus store for 10 cents each and used them for scale models detail. I may still have one saved somewhere.

 

[tyrodtom]

During the Vietnam war they had the lazy dog, a about 2 inch, maybe 1/2 pound , like a tiny little bomb with fins.
I think it was left over from the Korean war.
We were told fantastic tales about how deadly it was, but we were told fantastic tales about how effective ever weapon we used was too.

 

[GrauGeist]

My Uncle gave me a handful of Lazy Dogs when he was on leave during Vietnam.
They were the forged version (the other was lathe-turned) and a dark green.
I could see those doing damage, being about 6 or 7 ounces, fin-stabilized and falling at terminal velocity.

 

[yosimitesam]

Most of the bullets that missed went into the Phantom Zone. A smaller percentage went into the Twilight Zone. The rest....?

Quote from the BoB:

Butler: "We are having crumpets for tea, sir. Oh, and they are machine gunning the rear garden."

A few probably went into that 'space-time wormhole' which also manages to grab one sock from my dryer load sometimes, because the one missing sock is never found. It's probably floating along outside some distant galaxy, somewhere. My theory is the circular motion of the tumble dryer somehow causes this 'wrinkle' in the space-time continuum, although I lack an adequate theory for the other crap I own, all of which will eventually dissappear, one object at a time.

 

[SaparotRob]

That does seem to explain a number of mysterious disappearances from the Bermuda Dryer/washer.

 

[fubar57]

Believe it or not, one day while I do doing my work clothes laundry, I noticed some fabric sticking out from under the door seal of the front loading washer. I moved the seal back and lo and behold....the world's supply of sock singles

 

[SaparotRob]

Notify the Dark Skies channel!

 

[pbehn]

Believe it or not, one day while I do doing my work clothes laundry, I noticed some fabric sticking out from under the door seal of the front loading washer. I moved the seal back and lo and behold....the world's supply of sock singles

I think you have discovered a sock portal, the time space continuum is at risk, do you have dilithium crystals at hand, Scotty used swear by them in these situations.