Eleanor416Rigby
Member
Do you have a formula to calculate how far downrange the sound of a gunshot will catch up with the bullet?
Any of the usual ballistic programs will give time of flight for the bullet. If you know the speed of sound at the ambient conditions, it is not hard to figure.
I don't know the answer, but it might be never if I understand the question. Are you asking at what range would someone be able to hear the gunshot at the same time or before the bullet arrives? Most rifle bullets start out 4-5X the speed of sound and are still double the speed of sound at 1000 yards. That is quite a head start. Considering roughly 30' of bullet drop at 1000 yards it would be pretty hard for someone to hear a shot fired at them before the bullet hit the ground or was already past.
The only scenario I can thing of is firing a shot up at a very steep angle. The bullet may well travel quite a distance up and back down, but only strike the ground a short distance away.
Sound is not affected by gravity.I was wondering if, like the bullet, the sound of the rifle shot also hits the ground?
Good man! I like your sense of humor.I was wondering if, like the bullet, the sound of the rifle shot also hits the ground?
Or black powder cartridge rifles. My Shiloh Sharps .45-110 launches a 500 grain bullet at about 1,350fps - just a couple of hundred fps faster than the speed of sound in air. Yet that 500 grain bullet can arrive on a distant target a full 2 seconds before the report from the rifle gets there. And I know that's true because I saw it in the movie "Quigley Down Under" - which I own a copy of.Think muzzleloaders.
Good man! I like your sense of humor.
In three weeks, there will be a mountain man rendezvous held on the other side of the valley, right at 2.5 miles from our house. We'll be able to hear the reports from the muzzle loaders, and especially the reports from the cannons, on our back porch. Unlike our gun-shy Cocker Spaniel, we look forward to it every year.That's interesting. I guess I've heard rifle and pistol shots that were in the neighborhood of a couple miles off, but it wasn't exactly measured distance.
that the rate of drop in bullet velocity is linear over time and distance.
The drag on the bullet surface declines (not linearly) as the speed declines (not linearly); therefore the drag force is not constant. The decrease in velocity, likewise, decreases with the decreasing drag that results from the decreasing speed. In other words, we need calculus.
A bullet with a BC of .5 started at 3000 fps will be going about 1400 fps at 1000 yards, depending.Even the fastest bullet in the record books will be well below the speed of sound at 1000 yards.
A bullet with a BC of .5 started at 3000 fps will be going about 1400 fps at 1000 yards, depending.
A bullet with a BC of .1 started at 2000 fps will travel about 1200 feet in 1.1 second.
A bullet with a BC of .1 started at 2500 fps will take about 4 seconds to go 1000 yards. The sound would get there more than a second ahead of the bullet.
My claim about the fastest bullet in the books was based on the 220 swift, which does not have a BC anywhere near .5. Most bullets don't have BC of .5, but if you can get one going 3000 fps, it will retain speed a lot better.
This might be true (likely is) for something like the 220 Swift you mentioned, but is absolutely not true for many other calibers used for long range shooting. 50 BMG's starting out at 2750 fps can stay supersonic...depending on the projectile....well past 1500 yds and the 338 Lapua over 1800 which is why they're often chosen for extreme long range shooting. The newer VLD bullets fly really, really well....so long range isn't bothered by that pesky sound barrier thing getting in the way on the way back down.Even the fastest bullet in the record books will be well below the speed of sound at 1000 yards.
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Thank you. Actually, I know you can use TOF, which some ballistics programs calculate, and figure it out, but I'm one of those guys who likes to figure out square roots by hand, and make ice cream in a hand-crank bucket. I've taken a few courses in physics, but I don't remember how to set up the math to figure this one.