How high would it go?

[Ray B]

Say you mount a rifle in the vertical position, pointed straight up on a 747 and during the flight the plane is level at 35,000 feet. The weather/pressure is 30" at sea level, which charts show would be 7 at the plane's altitude of 35K; 40K 5.5; 45K 4.5; 50K 3.4; 55K 2.7; 60K 2.1; 70K 1.3; 80K .8. The rifle shoots a bullet with BC .8 and muzzle velocity 3300 fps.

So for those of you with ballistic calculators: 1. How high would the bullet go before it stopped and started falling back to Earth? and 2, What would it's time of flight be?

 

[Wyatt Smith]

Have you ever watched the myth busters episode where they fired the rifle (M1) into the air to see where the bullet would land. I think they were trying to get the bullet to land back on the rifle. They may have mentioned a max height.

 

[sestoppelman]

Higher than I can jump! Think we need a new section for Covid questions!

 

[bruce moulds]

tests were done on this at sandy hook using 45/70s.
they waited for the bullets to fall into a lake.
can't remember the results.
bruce.

 

[Forrest Halley]

tests were done on this at sandy hook using 45/70s.
they waited for the bullets to fall into a lake.
can't remember the results.
bruce.

I thought the Sandy Hook tests were done for penetration and dispersion at extremely long ranges. They studied optimum firing angles and powder charges and angle of attack at impact.

 

[bruce moulds]

forrest,
your description of sandy hook is absolutely correct.
i thought i remembered the inclusion of vertical shots there as well.
if i am wrong, the tests came from hatchers notebook, and were probably not with 45/70.
i read both of these a long time ago.
bruce.

 

[Forrest Halley]

Bruce,
The mere fact that you recalled those tests is tribute sufficient. I am but 36 and the thought of folks doing something like that to further the ballistic knowledge is quite impressive. I would have enjoyed being around for that. All the free ammunition and targets aplenty. There is a pond on Sandy Hook, but I have never read of the vertical tests. Search ".45-70 at Two Miles: The Sandy Hook Tests of 1879" for an interesting read or refresher.

 

[Tra3]

@Forrest Halley thank you for the info! I just read about the .45-70 tests at 2 miles. Fascinating to think about the time they put into that test. And to think 30 degrees or less achieved the maximum distance, very interesting.

 

[Forrest Halley]

@Tra3 you're welcome. I marvelled at how close to indirect fire this was. Almost like the machine guns at Iwo Jima. I admire the ballistic optimization for sure. Imagine if they had tried something like a gas checked boat tail at those ranges or even a paper patched bullet. I know now that my .458 Lott can pierce antifan shields at almost four thousand yards. That makes me feel much better.

 

[fourfive8]

One of those things that gets covered now and then on some of the odd tv shows

An '06 bullet reaching 10,000 ft is surprisingly high, if I think about it a bit. However it's the terminal velocity of the descent that gets the most press especially around 4th of July and New Year's in cities as all the celebrating idiots start shooting. The maximum descent terminal velocity of an average 30 cal bullet fired straight up would be no greater than about 300 fps. Likely a lot less as that maximum is based on the bullet falling point first. In reality the bullet would likely start tumbling or yawing wildly around it axis as it descended thus increasing the air drag and decreasing the velocity. The US Army conducted these tests for small arms and concluding the 300 fps max was not sufficient to classify as potential for severe wounding for tactical military purposes. However that doesn't mean a falling bullet at something between 100 and 300 fps isn't dangerous and kills or seriously injures people each year.

Julian Hatcher calculated that an M2 30-06 bullet fired straight up would take 18 seconds to reach it's apex of about 9000 feet and 31 seconds to descend.


Simple table showing some data

Maximum Altitude For Bullets Fired Vertically | Close Focus Research - Ballistic Testing Services

www.closefocusresearch.com

 

[Ray B]

The formula that was developed for calculating the decrease in velocity for the vertically fired bullets is what is needed for this calculation. The problem with the existing charts is that it uses drag based on sea level barometric pressure. What I would like to know is the result when it is fired at less than 1/4 of the pressure and proceeding through air that would apply very little drag. the final determinant of the height would be the bullets capture by gravity, but as has been said, this is very little force as compared to the drag of the atmosphere.

 

[Randy F]

My question would be;
Is anyone dumb enough to stand there looking up waiting for it to fall?
I think we all know at least one to lay a wager on.

 

[WAB]

When we first moved from New Brunswick, Canada to Wyoming (many, many moons ago), we were shocked on New Year’s Eve when hundreds of people ran outside at midnight and fired their guns in the air. I was on top of one of the tanks at the refinery the next day and the operator picked up a number of spent bullets. Seemed like an odd practice to this Canadian farm kid. They didn’t damage the tank roofs but I suspect that a lead slug at terminal velocity would hurt if it hit you.