Theory: Bullet drop - Page 4

exLupo · 2011-08-10, 05:07 AM

Originally Posted by Sirisian

That doesn't make sense. Rifling stabilizes the bullets straight flight. There is no force that would cause the bullet to go down then come back up. I've taken a few physics courses and know a bit about guns. The rotation is only for stability. It doesn't spin fast enough to actually impart any force like a hop-up would. Thus there's no force acting on the bullet when it leaves the gun that would cause it to dip down or raise up against gravity. It's just not possible.

To back up this post, I'll take a quote from the same page with the stats link earlier.

Starting with:

One of the more pervasive myths associated with bullet trajectory is that "bullets always rise right after they leave the barrel." In general, bullets do rise after leaving the barrel, and they immediately begin to drop. This is not a contradiction, and the explanation is not difficult to understand.

Source

The gyrojets mentioned in a previous thread could possibly exhibit a wave but that's because they accelerate after firing so, in theory, could propel themselves above the exit tube's axis. However, that's additional propulsion and projectile angle. Missiles, jets off a carrier, etc. The only time you get dip and rise is with a self propelled article.

cashfoyogash · 2011-08-10, 09:54 AM

Originally Posted by Sirisian

That doesn't make sense. Rifling stabilizes the bullets straight flight. There is no force that would cause the bullet to go down then come back up. I've taken a few physics courses and know a bit about guns. The rotation is only for stability. It doesn't spin fast enough to actually impart any force like a hop-up would. Thus there's no force acting on the bullet when it leaves the gun that would cause it to dip down or raise up against gravity. It's just not possible.

Ok you took a few physic courses and that just counters the few years of experience I have in the actual infantry training with this casualty producing weapon. If it were to be put into a degree I would have a bachelors degree in putting ass to foot with the assault rifle. Not to mention the men who told me that the bullet has a slight dip when it leaves the barrel would have a masters degree in putting foot to ass with the rifle. Physics may make you smart but it dont make you an expert in anything to do with the assault rifle.

CutterJohn · 2011-08-10, 10:15 AM

There is no dip. You may have experience with the rifles, but your understanding of bullet trajectories is flawed. They follow a simple arc, nothing more. The bullet starts below the line of sight, travels up because the barrel is pointed slightly up, then falls back. M16s have to aim quite low at close targets because the sights are unusually high.

cashfoyogash · 2011-08-10, 10:20 AM

Originally Posted by CutterJohn

There is no dip. You may have experience with the rifles, but your understanding of bullet trajectories is flawed. They follow a simple arc, nothing more.

I highly doubt that my drill sgts were flawed when they were explaining this to us...

CutterJohn · 2011-08-10, 10:29 AM

Originally Posted by cashfoyogash

I highly doubt that my drill sgts were flawed when they were explaining this to us...

I think they were confused, or you were. Believe what you will though.

http://www.google.com/search?rlz=1C1...w=1130&bih=971

Or here. You think your instructors were more versed in bullet trajectories than engineers at winchester?

basti · 2011-08-10, 11:24 AM

Wow, this thread really derailed in a direction no one would have guessed.

Ridill · 2011-08-10, 12:07 PM

Originally Posted by CutterJohn

The state of your education is worrying. Thankfully others have pointed out your errors so I don't have to.

I'm all for bullet drop on all weapons it should not reasonably apply too, along with a more reasonable damage degradation with range. Make compensating for the drop what is necessary to be effective at those long ranges, not a magical lessening of energy.

As for vanu weapons: They should not have no bullet drop. They are still shooting matter, and that would still suffer from the effects of gravity. Shot speed is what you want to flatten out the arc. A lashers orbs would should have lobbed like softballs. A lancer and mag railgun should have had a noticeable arc, though being fast projectiles it would not have been much.

If its not a laser, or perhaps a railgun with hypersonic bullets, there must be arc.

People from other countries oft give those in the US shit for not knowing other languages. Learn to use more than one measuring system. The simple conversions are easy, and you can derive the rest.

Ok I'll bite. Tell me how my education is worrying as nothing I said was incorrect? Was I totally owned when that guy did those fancy calculations using the speed of light as a constant of 3,000,000 miles/sec? MY EDUCATION IS WORRYING?

I thought I was being clear in my intention, but it seems there was some ambiguity here as people seem to be under the impression i'm asking for light drop to be included in the game. I was merely making a play at realism in a game like planetside while taking a jab at the OP. Something just stood out as ridiculous for me with his in regards to "kids" and the way things should be. Where do you draw the line on importance in things like bullet drop. With weapons named "beamer" one can only assume it is lasers they are shooting even they though no resemblence of that in physics.

Edit: Oh and yes, using anything other than metric for unit based calculations and conversions is stupid. Yes I am American.

NapalmEnima · 2011-08-10, 01:19 PM

Originally Posted by Sirisian

And this isn't caused by any upward recoil of the rifle that would give the impression of the bullet dropping then coming back up as you quickly adjusted? From a physics standpoint there's nothing to explain such action and I can't find anything online to support that idea.

I must agree with Sirisian on this one. OTOH, I'm open minded.

Lets go have a look at some high-speed "bullet leaving the barrel" videos on youtube, eh?

Nothing magical here, but that's a Very Short slice of time.

http://www.youtube.com/watch?v=otpFNL3yem4

The first 15 seconds or so of this video give a better view of the round as it travels a bit.

http://www.youtube.com/watch?v=lL0-SpI2u4U

Nothing magical there either.

Now if you look at something like a paintball gun where the projectile is spinning on a different axis, you can get some Strange Things (like the tippman flatline, or a little water/paint in your barrel).

Oh, and here's one that simply demonstrates how epic slo mo can really be:

http://www.youtube.com/watch?v=kag4tU6B3yc

So no. The training cited is probably dumbing down What Actually Happens so your well below average Derp-a-Derp bullet catcher has something they can work with.

cashfoyogash · 2011-08-10, 02:05 PM

Originally Posted by CutterJohn

I think they were confused, or you were. Believe what you will though.

http://www.google.com/search?rlz=1C1...w=1130&bih=971

Or here. You think your instructors were more versed in bullet trajectories than engineers at winchester?

Ok that was suppose to show me what exactly? I told you there is a slight dip coming out the barrel. Find yourself a soldiers handbook the diagram is in there for it. I dont see how anyone can argue against people that actually do this for a living. The bullet dips get over it.

Surge72 · 2011-08-10, 02:20 PM

Originally Posted by cashfoyogash

I dont see how anyone can argue against people that actually do this for a living. The bullet dips get over it.

Probably because there is no explanation given for why it would do that? Until you explain why it follows this behaviour, people are just going to assume you are misinterpreting what is happening when see it yourself.

EASyEightyEight · 2011-08-10, 05:01 PM

Originally Posted by basti

Wow, this thread really derailed in a direction no one would have guessed.

Smart people trying to outsmart other smart people. And I'm so dumb

I just simply realize SOE isn't going to be using real world physics on their weaponry in game. At least, I don't think they will. They'll more than likely follow the KISS example: bullet goes to where cross-hair is, generally, until a certain point them simply drop severly.

And for the record: I don't think SOE intends for Vanu plasma fire to move at the speed of light.

Furret · 2011-08-10, 05:11 PM

Originally Posted by cashfoyogash

Ok that was suppose to show me what exactly? I told you there is a slight dip coming out the barrel. Find yourself a soldiers handbook the diagram is in there for it. I dont see how anyone can argue against people that actually do this for a living. The bullet dips get over it.

Your point is exactly valid. You can't argue with people who actually do this for a living. Though you're wrong on who has the most expertise.

You just shoot the gun for a living, other people STUDY WHY AND HOW IT WORKS for a living.

Timmy · 2011-08-10, 05:37 PM

Originally Posted by cashfoyogash

Im telling you there is a small dip when it first leaves the barrel.... how could the us army be wrong? it is who taught me how to shoot and it has a very slight dip when it first leaves the barrel to which it then elevates up to the line of sight to whatever range your zeroed in at then it starts to fall. It is why when we aimed at the closest target we aimed in the dirt.

I think your only excuse at this point is if your instructor was Lee Harvey Oswald because your describing a Magic Bullet that defies the laws of physics.

Originally Posted by cashfoyogash

Ok that was suppose to show me what exactly? I told you there is a slight dip coming out the barrel. Find yourself a soldiers handbook the diagram is in there for it. I dont see how anyone can argue against people that actually do this for a living. The bullet dips get over it.

By your own reasoning, the Winchester link was made by people who do this for a living and there's no dip - so why don't you believe them?

http://8reg.txsg.state.tx.us/Manuals..._4.9412913.pdf

Here's one and the only Dip I see is you. You said your self that your sights are set for 175m distance. That's what you call "Zeroing" them in. Because if your barrel is at "zero" and your sights are a few centimeters above "zero" it will make you point the gun at the right angle so that when the bullet travels 175m it will drift/drop back to "Zero." You aim "low" at a close target because your sights, being a few centimeters above the barrel, are still at the proper angle (relative to the muzzle) to make you hit a target at 175m.

I know you don't want to hear all the fancy-talk from the learned-folk that know physics, so let me give you as foot-to-ass example you and Sarge can wrap your brain around.

When Bo and Luke jump the General Lee, have you ever seen it dip first then go up?

You can lead a horse to water but you can't make him drink.

And why has everyone in this thread been so nice to the guy that thinks light moves at 3,000,000 miles per second? He even typed it out in case we thought he couldn't be that stupid and made a typo...

Originally Posted by NapalmEnima

1) The speed of light is 3,000,000 miles per second (give or take). Three Million miles per second.

3,000,000 (give or take 2,800,000)

http://en.wikipedia.org/wiki/Speed_of_light

299,792,458 m / s means "Meters per Second" or 186,000 Miles per Second

Furret · 2011-08-10, 05:52 PM

We gave him a break because he was doing calculations with the Imperial system, and only mentally challenged people do that if they don't have to. Just tryna give him the benefit of the doubt.

Rbstr · 2011-08-10, 06:11 PM

Originally Posted by Furret

Your point is exactly valid. You can't argue with people who actually do this for a living. Though you're wrong on who has the most expertise.

You just shoot the gun for a living, other people STUDY WHY AND HOW IT WORKS for a living.

This. Technicians (in this case soldiers) often have a wonderful understanding of how to use equipment but often have little idea of how the equipment actually functions. Turn this dial this much and get this result...but no real idea what the dial does.

A pitcher knows what to do to get a ball to curve, and even that it's based on spin. But no idea that a baseball is an amazing coincidence of fluid dynamic phenomenon.

A bullet that shows some kind of lift (beyond the barrel angle effects) wouldn't be impossible, it could exchange velocity or angular momentum for height...but they don't because they aren't designed that way.

Rob, I assume what you ment on my comment about coriolis force was in refrence to weather. Yea I get that.

Not quite...you said it wasn't a force, but it is...if you look at an object in a rotating frame the coriolis effect manifests itself as a force. When this kind of thing happens they're called fictitious forces. http://en.wikipedia.org/wiki/Fictitious_force