A bullet travels how fast ?

getitdone1 · Post by **getitdone1** » Sat Feb 02, 2008 11:59 pm

Ever wonder how fast a bullet travels in miles per hour? No doubt many of you have done the numbers and found the answer.

I've figured the numbers in the past but forgot so did a little figuring awhile ago.

3000 fps = 2,045 mph

1200 fps = 818 mph

Related:

Speed of sound = 770 mph or 1130 fps
Sound travels faster in liquids and solids and varies w/temperature.

Speed of light. (Oh boy! This gets "way out there!")

Speed of light = 670,616,629.2 mph or 186,282.3 mps

SO YOU THINK YOUR RIFLE IS FAST ??

Experiments have attained speeds faster than "Light Speed."

Just thought some of you would find this stuff interesting.

Don McCullough

Post by **Ysabel Kid** » Sun Feb 03, 2008 12:17 am

Cool!

Post by **Old Savage** » Sun Feb 03, 2008 1:16 am

So, slightly more than 2/3 of the fps in mph.

Bigahh · Post by **Bigahh** » Sun Feb 03, 2008 1:41 am

I just knew there was an Engineer somewhere in the Group!

Leverdude · Post by **Leverdude** » Sun Feb 03, 2008 2:13 am

I'm amazed when I think of the rotation. A 3000fps bullet from a 1 in 12 bore is spinning 3000 RPS, thats 180,000RPM & some spin faster than that. Alot of stress to place on a hunk of lead sheathed in copper eh?

JReed · Post by **JReed** » Sun Feb 03, 2008 2:17 am

Ouch that just made my head hurt.

Griff · Post by **Griff** » Sun Feb 03, 2008 2:19 am

My head aches when I think how many tons of energy they transfer! But, then I cheer up when I realize how long its been since I've had one hit me!

Bronco · Post by **Bronco** » Sun Feb 03, 2008 2:49 am

Howdy,
What blew my mind, easily done, is that if a SR-71 could fly at full speed close to the groung it could overtake and run into a 180gr. bullet out of a 30-06.

Man oh man.
John

Post by **Old Savage** » Sun Feb 03, 2008 2:54 am

And it flies much faster than they said it would.

Bronco · Post by **Bronco** » Sun Feb 03, 2008 3:07 am

Yep,
Only publicized enough to break know records. I heard tell........ fast MF.
John

TedH · Post by **TedH** » Sun Feb 03, 2008 8:37 am

They probably have something now that is even faster that we don't know about. How long were they using the SR-71 before the public was informed?

rhead · Post by **rhead** » Sun Feb 03, 2008 9:38 am

Try calculating the rotationial velocity of the surface of a spinning bullet.

brucew44guns · Post by **brucew44guns** » Sun Feb 03, 2008 10:03 am

In McPherson, Kansas is a space museum open to people, a complete SR 71 hangs from the ceiling of the main showroom, and is only a little bit over the top of your head. When I went there once, I almost skipped the rest of the exhibits, just standing in awe of this fabulous black machine.

getitdone1 · Post by **getitdone1** » Sun Feb 03, 2008 10:32 am

Now I'm getting way off topic but while we're into numbers, try these on:

Circumference of earth = 24,901.55 miles--at equator
Light Speed can travel around earth at equator 7.48 times in 1 second !!

Earth spinning about 1,038 mph at equator
U.S and Europe spinning from 700-900 mph
North Pole spinning almost at 0 mph
Average distance to moon = 238,857 miles--be a long shot

Hey, but we did it !
Earth 70.8% water--29.2% land. Interesting that animal tissue is composed of about 66% water.
Age of earth--4.5-4.6 billion years old
Earth population = 6.6 billion
Higest temperature--135.8 Libya
Lowest temperature-- -128.5 Vostok Antarctica
Really great spread between these two temperatures.

How amazing it is that the earth just happens to be the right distance from the sun. Too far and too cold for humans. Too close and too hot for humans. Can anyone here tell us how far the earth would have to move from it's orbit before we'd be in BIG TROUBLE ?

I got on these fascinating numbers and my curiosity got to working.

Reminds me of the saying: "It's all relative." Guns are fast but very slow when compared to the speed of some things.

Edit: I forgot to include a very fascinating fact:

The speed of light is 670,616,629.2 mph. Astronomers speak in terms of "light years" when discussing the distance between objects in outer space. That is, this object in space is so many light years away from the earth or another object. Now since light goes over 670 million mile per hour can you imagine how far it would travel in a year? And yet they often speak in terms of many light years distances. As far as they know outer space has no end. Really "far out" as we used to say when I was a teenager.

Don McCullough

Yodar · Post by **Yodar** » Sun Feb 03, 2008 11:10 am

Any of you smart guys know how hot a bullet gets on its flight from muzzle to target? The reason I ask is that we had small brush fire at our range last Spring that the Forest Service investigator blamed on a "hot bullet" that ignited dry grass around 200 plus yards from the firing line.

It is not clear which alledged bullet started the fire; if it did at all. It could have been a .223, or a 7mm Mauser, or a .308 jacketed bullet.

The investigator did not offer any proof as to the temperature of a bullet. He just said that was the way it happened and the club was responsible.
Personally, I think he is full of you-know-what. He may have been under pressure from his superiors to find fault with the club becasue the club is on leased National Forest land and they would like to kick the club out when the lease is up in 2014.

I posed this question in a lettter to the NRA technical staff last August. To date, I have not received a response.

Anyone have an answer?

Leverdude · Post by **Leverdude** » Sun Feb 03, 2008 11:26 am

I dont think it gets hot enough to start a fire. The core would melt.
Its probably cooling off really. The friction from air cant create more heat than the friction of going thru a tight fitting rifle bore.
Plus I'v shot lotsa wooden things & none got scorched.

pharmseller · Post by **pharmseller** » Sun Feb 03, 2008 11:28 am

More fun stuff:
Can you remember this sentence?

Mother very thoughtfully made a jelly sandwich under no protest.

Mercury, Venus, Terra (Earth), Mars, asteroid belt, Jupiter, Saturn, Uranus (giggle), Neptune, Pluto

This works for as long as Neptune remains outside of Pluto's orbit, which should last another few thousand years or so.

Quinn

AJMD429 · Post by **AJMD429** » Sun Feb 03, 2008 11:47 am

Leverdude wrote:I'm amazed when I think of the rotation. A 3000fps bullet from a 1 in 12 bore is spinning 3000 RPS, thats 180,000RPM & some spin faster than that. Alot of stress to place on a hunk of lead sheathed in copper eh?

That's something to think about - bullet RPM actually depends not only on rifling twist, but velocity as well.

So, a lighter bullet of the same construction as your normal one would be shorter, and have plenty of RPM, even if the velocity (and therefore, RPM) were no greater.

But IF your bullet instead of being shorter, is lighter weight because it is in a sabot (so it is actually a longer, skinnier bullet), or because it is a solid copper (longer, same diameter), it will in fact need a faster RPM, all else being equal. Fortunately, it will usually be going enough faster that it will get that RPM even if the rifling twist is 'slow.'

Going the other way, to heavier bullets, they really HAVE to be longer than the originals, so they really have to have higher RPM to be stable; there's the rub - because without a higher twist rate you'll have a hard time pushing the heavier bullet faster to get that RPM.

At least that's the way I understand it...

chuckles · Post by **chuckles** » Sun Feb 03, 2008 11:59 am

Bronco wrote:Howdy,
What blew my mind, easily done, is that if a SR-71 could fly at full speed close to the groung it could overtake and run into a 180gr. bullet out of a 30-06. Man oh man.
John

Someone once told me that if you fired a 30-06 bullet to New York from LA and the SR-71 left the same time, if the 30-06 bullet could maintain its muzzle velocity the entire 3000 miles, the SR-71 would get to New York 20 minutes ahead of the bullet. He was a AF fighter pilot and he had tried to get into the Blackbird Squadron at Beale AFB and couldn't get in. He said they only selected the best of best. It was his life's disappointment, (according to him). One fast jose that one.

chuckles · Post by **chuckles** » Sun Feb 03, 2008 12:00 pm

Bronco wrote:Howdy,
What blew my mind, easily done, is that if a SR-71 could fly at full speed close to the groung it could overtake and run into a 180gr. bullet out of a 30-06. Man oh man.
John

Someone once told me that if you fired a 30-06 bullet to New York from LA and the SR-71 left the same time, if the 30-06 bullet could maintain its muzzle velocity the entire 3000 miles, the SR-71 would get to New York 20 minutes ahead of the bullet. He was a AF fighter pilot and he had tried to get into the Blackbird Squadron at Beale AFB and couldn't get in. He said they only selected the best of best. It was his life's disappointment, (according to him). One fast jose that one.

Post by **Old Savage** » Sun Feb 03, 2008 1:48 pm

The only fired that started at our range was by some one shooting tracers. Plenty of hot bullets into dry brush for 20 years in the summer 105 to 110 degree heat don't do it.

Dastook · Post by **Dastook** » Sun Feb 03, 2008 3:01 pm

Leverdude wrote:I'm amazed when I think of the rotation. A 3000fps bullet from a 1 in 12 bore is spinning 3000 RPS, thats 180,000RPM & some spin faster than that. Alot of stress to place on a hunk of lead sheathed in copper eh?

That is the main factor in bullets coming apart, especially the very high velocity calibers. It is from centrifugal force. Very little pressure needs to be applied to the nose of these bullets to make them come apart.

bogus bill · Post by **bogus bill** » Sun Feb 03, 2008 3:22 pm

I was a security guard at lockheed from 1965 to 2000. I was around the SR-71 a lot and knew many of the pilots. I cant off hand remember the figuers I heard without research, but it is faster then they will say.
I once heard a radio call of a pilot that he was over salt lake city and would be landing at palmdale, calif in, I am probley inaccurate in this, but I want to say something like 11 minuets. We would get a heads up as we had to open the fly-way gate to let them in the plant.
I used to fly myself and still own a citaberia that is being restored. A long story. Anyway back in the late 70s I was flying near plant 42 with a friend. I was legal, going to cross over the plant at the right legal altitude in my citaberia. I heard a call that a SR-71 was makeing a touch and go.
I watched him do the touch and go under me. He climbed out to the west and made a climbing turn and it was almost unbeliveable as now he looked like a arrow intercepting me! I started to roll over to do a split S to avoid. He shot past ahead of me and I could actualy see the back seat navigaters head turned looking towards us! Neither me or those guys can or will say, but it was a little closer than we should have been!

Leverdude · Post by **Leverdude** » Sun Feb 03, 2008 3:24 pm

Dastook wrote:
Leverdude wrote:I'm amazed when I think of the rotation. A 3000fps bullet from a 1 in 12 bore is spinning 3000 RPS, thats 180,000RPM & some spin faster than that. Alot of stress to place on a hunk of lead sheathed in copper eh?
That is the main factor in bullets coming apart, especially the very high velocity calibers. It is from centrifugal force. Very little pressure needs to be applied to the nose of these bullets to make them come apart.

Yup. My boss & I were discussing ricochets not long ago. He's got a nice hunting spot that he talked the lady into permitting shotgun only because of ricochets. I tried explaining that his 1500 fps slug was more dangerous that an 06 in that regard but he couldn't or wouldn't understand that the hunk of lead was going to bounce & keep going but a rifle bullet would unstabilize as soon as it wasn't gyroscopically stable & either come apart or fizzle out soon.

AJMD429 · Post by **AJMD429** » Sun Feb 03, 2008 3:32 pm

getitdone1 wrote:How amazing it is that the earth just happens to be the right distance from the sun.
Don McCullough

I was going up a long on-ramp to an elevated highway aimed directly into the sun, and mused about what if I could get the truck up to 1,000 mph how long would it take to the sun.

I think the sun is 90+million miles away, so we'd be talking 90+thousand hours, divided by 365 divided by 24, or over ten years to get to the sun, going 1,000 miles an hour...!

jd45 · Post by **jd45** » Sun Feb 03, 2008 9:10 pm

getitdone1, does this not speak to you of the concept of a supreme being designer & creator? It does to me, jd45

BAGTIC · Post by **BAGTIC** » Thu Feb 07, 2008 1:35 pm

Twist rate has nothing to do with the bullet. Twist rate describes the barrel. It does not change.

The rotational rate, rpm's, etc. varies with bullet velocity but not necessarily with bullet length or weight.