Monkey Spanker
Well-Known Member
Oh no. Not this old chestnut...again? As I've written before militaries have spent huge amounts of time on researching this because of the wish to assess the risk of bullets falling to earth from high angle anti-aircraft defence causing casualties amongst the very troops that have just fired them.
There's documented conclusions in most of the major sources of serious small arms research from the 1920s and 1930s and not the made for TV pseudo science of the American "Mythbusters" programme.
So here's something from a RESPECTED American authority:
From"Official Report of Vertical Time of Flight for Small Arms Ammunition" (U.S. Army Ordnance Office) expain this.
"The firing platform at Miami was about ten feet square. There was a shield of thin armor plate over the heads of the men at the gun. Out of more than 500 shots fired after adjusting the gun so as to bring the shots as nearly as possible onto the platform, only 4 shots hit it, and one more fell into the boat. One of the shots that hit the platform was a Service .30-'06, 150 grain flat based bullet which came down base first and bounced into the water after striking the edge of the lower platform. It left a mark about 1/16 inch deep in the soft pine board. Two more bullets struck in a pail of water beside the machine gun.
"It was concluded from these tests that the return velocity was about 300 feet per second. With the 150 grain bullet, this corresponds to an energy of 30 foot pounds. Previously the Army had decided that on the average, an energy of 60 foot pounds is required to produce a disabling wound.
"Calculations indicate that the 150 grain .30 caliber Service bullet fired straight up at a muzzle velocity of 2700 feet per second will rise 9000 feet, taking about 18 seconds to do it; and that it takes 31 seconds to return to earth, the last few thousand feet of the fall being at a nearly constant speed of a bit over 300 feet per second.
"If this same bullet were fired in a vacuum upwards at the same velocity, it would rise to a height of 113,000 feet. It would take nearly 84 seconds to make the ascent, and exactly the same time to come back, return with the same velocity that it started with".
Source(s):
Hatcher's Notebook, by Maj. Gen. Julian S. Hatcher. Copyright 1947, The Military Service Publishing Company. Third Edition, 2nd Printing. April 1966, pp. 510-518
As far as I'm aware, most Anti Aircraft fire is slightly larger than .30 cal (and I have been on the receiving end of it!)
I would also argue that a 150 grain bullet falling at 300 fps with an energy of 30 ft/lbs could kill - especially if tumbling and striking point first. I would not like to risk the integrity of my skull on some fairly basic research of almost 100 years old where one bullet hit a plank and 2 more hit a bucket of water! Every year there are dozens of people killed from bullets falling from the sky - FACT!
MS

just stalk ten feet down there and you will see deer i think he thought i was pulling his plonker, sure enough a nice big staggie walks off without a care in the world 