I shoot guns at a few local gun clubs and I have a range at my house and I always hear guys saying that bullets rise. I always just pretend that I didnt hear them and go on about my business. Wednesday I was shooting with a couple of my buddies and one tells the other that when you shoot a gun the bullet comes out and immediately drops and then begins to rise then it starts to drop again!!!! I asked him to explain to me how in the hell could a bullet do that!!!! The answer I got was that "the Marine Core snipers say that, and that is the way it is." Somebody please tell me that all these guys saying that a bullet will rise, are full of crap! If I am wrong please explain how the hell it does it!!!!!

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" Somebody please tell me that all these guys saying that a bullet will rise, are full of crap!

They are full of crap.....ask what force causes it.....and there is none!

Sounds like a false assumption based on bullet trajectory. With the sights mounted above the line of the bore, the fact that for the first 50 yds or so it is below the line of sight, then passes above it and then drops below again is being interpreted as the bullet falling, rising then falling again. It is always dropping toward the earth, it just crosses the line of sight twice.

Well, it depends on what you're comparing the bullet's trajectory to. Assuming the gun is held level, i.e. parallel to the ground, then in absolute terms, the bullet's going to start dropping when it comes out the muzzle and keep dropping till it hits something.

But that's not how we shoot a rifle. The scope and the barrel aren't perfectly parallel. Typically, the barrel is angled up slightly in comparison to the scope. So the bullet appears to rise—and literally does in comparison to the scope—before falling again once it passes the "zero" point.

So if you "zero" your rifle so that the bullet hits where you aim it at, say, 200 yards, then the bullet will appear to rise when it leaves the muzzle until some point before 200 yards when it begins dropping so that it will be "dead on" at 200 and "low" after that.

That gives us trajectory tables that look like this:

100 yards +1.5"
200 yards 0"
300 yards -7"

Because of the scope being above the bore, there will—again we're talking relative to the scope—be a slight drop until the bullet appears to rise and then drops again through the zero and on down.

But remember this only happens because the gun is angle up ever so slightly compared to the scope. If the gun is held parallel to the ground, then the bullet starts dropping immediately.

Clear as mud? Some of the challenge in understanding this is that guys like the ones you were speaking to don't really understand what they are talking about but they "know" it.

Play with the ballistics calculator at biggameinfo.com and you'll see this. Be sure to set the interval to 10 yards to illustrate this better.

LWD

That's hilarious!
Sounds like a guy I overheard at the range saying his 300Weatherby shoots dead flat out to 300yrds, then rises a bit @ 500 and beyond!

All bullets rise as they leave the barrel, above the line of sight, then fall to a point called the 'zero' range, that range at which the rifle is sighted in at.

If a gun is held perfectly level and fired over level ground, and at same instance it is fired another bullet of the same weight is dropped from the same height as the rifle, the two bullets will hit at the same time. Hard to believe but the person to argue about it is no longer available--it was Sir Issac Newton.
Back in the 40's Jack O'Connor wrote an article for Outdoor Life about sighting in a scope. The article was good enough that Weaver scopes made a reprint and included it with their scopes when Weavers were still made in El Paso Texas. This would have been from the 40's until in the 80's maybe 90's(not sure). The jest of the article is a bullet is pointed up but is being pulled by gravity thus it makes an arc (same as a baseball, basketball or footbal--they arc they don't go straight line). Line of sight is straight. He said sight in MOST hunting rifles at 25 yards they'll be inch or so high at 100 back on at 200 or thereabouts and be dropping past that. (Like Art described)

Cary-

Look at the graphs MickinColo posted. They are an excellent visual representation of what we're talking about. The middle one shows what the guys you were talking to described. They were right to the extent that the comparison is to the line of sight. But as the other graphs so it's all dependent on what the comparison is to.

LWD

I was also informed "it is a known fact that a .308 Win bullet leaves the barrel and immediately rises to the left, and it does this because of the rotation of the bullet and it also has something to do with the rotation of the earth!!!!!!!" But that is all the explanation I could get. I hear people saying crap like this all the time and on the very few occasions that I feel like I can keep my composure I'll ask them to explain it to me. Time after time we both fail!!! They fail to explain how it happens and I fail to keep my composure and laugh hysterically at them!!!

We were told the same thing in the military, when I was in.. just for exactly the reasons the above graphs show...

at the range with our M16s, if the target at 15 meters popped up, you were told to shoot at the dirt in front of it, as the bullet initially rises as it leaves the barrel...

if you aimed right at it and pulled the trigger, you'd shoot right over it...

Happened every time, and the knuckleheads who kept of missing claimed that the rifle and the sights on it were 'messed up'...

Never doubt what you hear from someone hanging around the gun club. They heard if from someone else, so it must be true. Besides, it fits with their general philosophy of life that says that anything that they've decided to believe (usually becasue believing it mitigates some personal shortcoming in intellectual capacity) must be factual regardless that all evidence and logic says otherwise.

It's the gravitation pull of the moon

The main problem is generalizing...and a ton of info on/in/around ANY forum is nothing but generalized BS.

If you know the answer, then you can expain it...somewhat...but if the level of understanding in your "subjects" is low or your own ablility do transfer that information in a cogent manor is faulty, then all that happens is mis-understanding and another source of BS...besides if you know the correct answer and the subject doesn't want to hear it, why bother and why get stirred up.

Humans are faulty to begin with...a perusal of ANY forum should show you that.

The "correct" answer was presented by several poster...IN GENERAL...but to nitpic and stir the pot even more...test studies have already been done that prove the bullet can actually rise or dip for a short distance which is totally dependent on velocity, barrel twist and direction, bullet shape and/or other factors...so depending on how the information was presented and in what vein and the level of understanding of the reader, the "actual" answer could be one of several...just to muddy the waters even more, so to speak.

PLUS...atmospheric conditions, gravimetric conditions, how you hold you mouth, can all play a role in lifting or depressing the curve of flight, bullet rpm has a large effect(in a very small dimention) on how the bullet "flies"...the bullet actually prescesssing around a central point viewed from the back end...some call that "corkscrewing through the air"...and many refer to that as "the bullet going to sleep"...some invoke the "Coriolis effect" of the spinning earth...we are all BULLSH**ERS to a certain extent or with differing levels or sizes of shovels...

For all intents and purposes and as far a "normal" shooting is concerned, the bullet starts dropping the moment it exits the barrel no matter WHAT angle the barrel is pointed or how the sights are set and continues to drop at varying levels of acceleration depending on a ton of "stuff", until it hits the ground or a target.

Mick presents an excellent pictorial representation of what is happening...and that representation depicts what happens in the real world absent all the "scientific BS" or other nitpicing.

Seafire...you might want to re-evaluate your thoughts...at 15M if you use your sights to aim with and the front sight is 2" high and sighted at 100M, Micks bottom chart will show you the bullet curve pretty close. Again, a whole lot of mis-information floating around kept buoyed up by mis-understanding.

It doesn't matter tho'...those that want correct answers will pursue them and develope what works best for them...the rest will be secure in their own understanding.

Some people get the Coriolis effect of the earths rotation confused with bullet yaw...very easy to do.

Forget the small stuff...let your targets do the talking.

Luck

I KNOW with a 7RM, the bullet will rise as it leaves the barrel and will shoot so flat that you can shoot out to 500 yards without a hold-over. I know this is true 'cause the fellow at the gun shop that was wanting to sell me the rifle told me so.

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Originally posted by wasbeeman:
I KNOW with a 7RM, the bullet will rise as it leaves the barrel and will shoot so flat that you can shoot out to 500 yards without a hold-over. I know this is true 'cause the fellow at the gun shop that was wanting to sell me the rifle told me so.

Damn, I hope you bought that rifle!!!! Will you sell it??

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I fail to keep my composure and laugh hysterically at them!!!

Ditto.

I once asked one of those guys what would happen if we fired the gun upside down. A dumb, vacant look for a few seconds, then a "light bulb" moment and a quick "The bullet will still rise." It' just magic, you know!

Such mental giants have no comprehension of the difference between 'line of sight' on a zeroed rifle and the 'line of bore/line of departure'. And you can't confuse many of them with facts either!

Once knew a guy, nice fellow actually, who told me he had a 'hard shootin' Marlin 336 in .32 Special. He said he recently shot a deer a mile away and dropped it. I asked how high he had to hold over, he replied, "Didn't hold over at all, that Marlin is a hard shootin' rifle!"

I only smiled and said "good shooting" that time.

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If a gun is held perfectly level and fired over level ground, and at same instance it is fired another bullet of the same weight is dropped from the same height as the rifle, the two bullets will hit at the same time.

Actually, no they won't.
The surface of the earth is curved, not flat.
The bullet dropped straight down will hit first.

quote:

Originally posted by Antelope Sniper:

quote:

If a gun is held perfectly level and fired over level ground, and at same instance it is fired another bullet of the same weight is dropped from the same height as the rifle, the two bullets will hit at the same time.

Actually, no they won't.
The surface of the earth is curved, not flat.
The bullet dropped straight down will hit first.

Unless, of course you are shooting over/into rising ground, as is found part of the time depending on whether there is hilly ground where you are shooting, and which direction you are facing there.


And exactly 31, 333 Angels dance on the head of each of my tailor's straight pins. (He is a consistent guy, with super-consistent pins. Maybe I can get him to make me a rifle....)

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Actually, no they won't.
The surface of the earth is curved, not flat.
The bullet dropped straight down will hit first.

Can you calculate the difference for us?.....

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Can you calculate the difference for us?.....

hmmmmm....

Earth's surface curves 1" every 220 yards.

From 5 feet, bullet would take .585 seconds to hit the ground.

That would give the .284 160gr AB at 3400 would travel 572 yards, and still be 2.6 inches above the ground. Fired bullet would hit the ground at 583 yards, and .598 seconds after being fired.

IN THEORY, the fired bullet would hit the ground .013 seconds later. Of course this is only for a bonded bullet. For cup and core, or solid copper bullets, the math is completely different!

quote:

Originally posted by Antelope Sniper:

quote:

Can you calculate the difference for us?.....

hmmmmm....

Earth's surface curves 1" every 220 yards.

From 5 feet, bullet would take .585 seconds to hit the ground.

That would give the .284 160gr AB at 3400 would travel 572 yards, and still be 2.6 inches above the ground. Fired bullet would hit the ground at 583 yards, and .598 seconds after being fired.

IN THEORY, the fired bullet would hit the ground .013 seconds later. Of course this is only for a bonded bullet. For cup and core, or solid copper bullets, the math is completely different!

Thats pretty damn impressive!!!!

Almost every statement above has a truth to it which is "fact" in a particular situation.

Physics is full of "facts" /Laws.
projectiles fired from a rifle or dropped from the hand.......... obey a common set of physical laws.........no exceptions.

The actual result depends on the test conditions & the context of the evaluation.
That result is valid in those test conditions & context ONLY.

Change any of the test conditions or the context of the evaluation of the result & the original "fact" becomes irrelevant.

The biggest mistake most humans make in discussing & applying facts is to receive information in one context & apply it in another.
- sometimes that is because the context is not well explained in the first case.
- sometimes that is because the recipient of the information has misunderstood the context of the information
- sometimes that is because the test conditions have changed.
- Most times its is because the 'giver' has not understood the context they received the information in & relayed it in another..........the 'receiver' has not understood the context of the information or its significance .........and both have intuitively assumed that because it worked over there it must work the same over here, because neither understood the significance of the context or change in conditions.

Myths are borne based on an out of context "fact".

almost every urban myth has its birth in such a situation.

relative to the departure angle of of a projectile from the bore it will fall after it leaves the bore.
No physical conditions exist in the real world of the outdoors & practical hunting,that can provide an upwards force greater than the gravitational force.

in the context of line of sight the above is not true.

Even the 'shoot at the 15M target by aiming at the dirt infront of it' has a truth where the firearm is not shouldered & a snap shot is taken from the hip..........as the line of sight has significantly changed.

line of sight & projectile path are 2 completely independent things........ at best they coincide twice ......at worst they never coincide before the projectile ceases flight.............

On a bad day the latter scenario describes my shotgunning

quote:

Originally posted by Antelope Sniper:

Earth's surface curves 1" every 220 yards.

From 5 feet, bullet would take .585 seconds to hit the ground.

That would give the .284 160gr AB at 3400 would travel 572 yards, and still be 2.6 inches above the ground. Fired bullet would hit the ground at 583 yards, and .598 seconds after being fired.

IN THEORY, the fired bullet would hit the ground .013 seconds later. Of course this is only for a bonded bullet. For cup and core, or solid copper bullets, the math is completely different!

Excellent AS

Question for everyone ( excluding AS ) for the testing of the theory
context & test condition.

How would you set up the rifle bore orientation

How would you set up the 600yd paddock.

Some interesting physics involved here.

DenisB, I would tell you how to set up the 600yd paddock... but I have no idea what you are talking about!! Way over my head!!!

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Earth's surface curves 1" every 220 yards.

My old brain couldn't do it in my head. I had remembered 8" per mile. Hey if you run that through your calculator it is 1" every 220yds.

Of course if you are on the edge of the South rim of the Grand Canyon these numbers are slightly off.
Peter.

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Originally posted by ramrod340:

quote:

Earth's surface curves 1" every 220 yards.

My old brain couldn't do it in my head. I had remembered 8" per mile. Hey if you run that through your calculator it is 1" every 220yds.

I ran it through autocad.....the software merely flipped a finger at me and said figure it out yourself!

If the ground is rising it is not level as Mr Newton's experiment stipulated.
Odd that the .308 spins one direction, wondered if you rechambered it to 30-06 would it still spin same way?

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Odd that the .308 spins one direction, wondered if you rechambered it to 30-06 would it still spin same way?

Oh, no. Short action cartridges spin one way; standard and magnum length cartridges spin the other.

If you hold the rifle upside down, barrel level, will it shoot opposite from right side up?

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Oh, no. Short action cartridges spin one way; standard and magnum length cartridges spin the other.

I was once told by guy who had a cousin who's wife's father knew a WWII naval gunner that said short action rifle bullets spin one way, long actions spin another but true magnum bullets spin the core one way and the jackets the other to cancel the spin effect so they can make hits at long range no matter which way the wind blows. From what I read and see on TV of 'hunters' blasting away at deer with super magnums at 800 - 2000 yards it must be true.
--------------------------

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If you hold the rifle upside down, barrel level, will it shoot opposite from right side up?

No. But the spin will cause bullet drift in the opposite direction and mess up your scope's zero.

If I removed the barrel and cutoff 1/2 thread and rechambered and reattached the barrel and then turned the gun upside down.....would the trajectory change?

An "acquaintance" of mine just came by to drop off two rifles. Pulled up in his CJ-7 with the stereo blaring at 8am. He wants me to sight them in for him before he goes hunting. Was wearing a black leather jacket, shades, and yes, he has tattoos.

He told me he "just knows" when a rifle is sighted in just perfectly. He shot a deer "way out there" while it was running with a rifle his brother sighted in "perfectly"

I told him to look at the rifle I was cleaning in the vise; my 6.5 Creedmoor in a McMillan A-5, Leupold Mark IV FF...

He walked over, stumbled and kicked my Dewey cleaning rod to the ground, tried to pull the rifle out of the vise while it was locked in, said "hey, a varmint rifle!", then went back to the running jeep with the stereo still blaring and roared off.

I opened the gun cases he left, checked the rifles, both had cartridges in the magazines.

Falls as soon as it leaves the barrel?

So.... if I aim and fire a rifle with the bore exactly plum with the earth when does the bullet start to fall???????
Let's say .284 dia. 150 grain bullet, with a 345 Bal. Coefficient leaving the muzzle at 2600 fps. fired from 600 feet elevation.
Oh, and 51 gr. of RL-22 with a 22" barrel and a
totally calm day with a barometric pressure of 50.

quote:

Originally posted by ramrod340:

quote:

Earth's surface curves 1" every 220 yards.

My old brain couldn't do it in my head. I had remembered 8" per mile. Hey if you run that through your calculator it is 1" every 220yds.

The Earth -not being a perfect sphere- does not have the same surface curvature at all points--



SSR

Boy, oh boy, did this relatively simple question stir up the fire and get the pot boiling.

Some are listening with understanding and some are still in denial.

Most of the "phenomenon" has been explained, proven, and illustrated, but it still boils down to personal bias as to which is what and why...always interesting to see the workings of the human mind.

Yeah...rca...there are many people that shouldn't be allowed to even look at guns, much less touch, shoot or own one...even toy ones.

Luck

The one answer that anyone needs to know: gravity works.

quote:

Originally posted by carpetman1:
If a gun is held perfectly level and fired over level ground, and at same instance it is fired another bullet of the same weight is dropped from the same height as the rifle, the two bullets will hit at the same time. Hard to believe but the person to argue about it is no longer available--it was Sir Issac Newton.

No disrespect intended, but I'm seriously hoping that I totally missed your point here. From what I understand you to say, shooting a gun shouldn't work at all, because the bullets would just tumble out of end of the barrel and hit the ground forthwith. Anyone who's shot even a pellet gun or a 22 knows it ain't so. Even an arrow from a bow, only going a few hundred fps, can fly through the air and overcome gravity for a little while.

I think the experiment you referred to actually had to do with 2 differently weighted objects (cannonballs I think?), and the point was that when dropped from the same height, they would hit the ground at the same time.

Maybe can you elaborate on what you're driving at here? Because to be honest, the way you wrote it doesn't make a lick of sense.

Davis

short answer

"yes, it looks like that, in a sighted in gun. However, any student of ballistics knows this to be an illusion as bullets are fired UP and sighting systems take advantage of this drop. Yes, the bullet does travel above the line of sight, then crosses it on the way down.. but it travels in an ARC, without lift, as a spinning symetric bullet has no lift"