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General Forums => Aircraft and Vehicles => Topic started by: Jigster on December 16, 2000, 12:13:00 AM

Title: Dispersion comparison
Post by: Jigster on December 16, 2000, 12:13:00 AM
 (http://bigdweeb.homestead.com/files/dispersion3.jpg)

 (http://bigdweeb.homestead.com/files/dchart.jpg)


Removed most of the errors from the one in this thread (ie actual comparison):
 http://bbs.hitechcreations.com/smf/Smileys/default/Forum1/HTML/006835.html (http://bbs.hitechcreations.com/smf/Smileys/default/Forum1/HTML/006835.html)

Basically, launched north, hit F5, max zoom, then panned until directly behind the plane. The images are different sizes because I cropped and they have different wing spans (and the Tiff shoots at a very high angle).
Then, expanded a circle from the center of the conversion point and expanded till it touched the tracer round(s) the furthest away from the center. This takes into account both the highest point of the arc (using the smoke trail for reference) and the lowest point. Using the rounds to the most outer point of the cone gives a circle, where anywhere inside there is a chance a bullet will strike a given point.

After making the circles I copied to another image for easier comparison. I'll prolly do these over again once 1.05 comes out to see what the change did.

Btw this isn't meant to be concrete by anymeans but it gives a fairly accurate account of how the guns disperse after 5 seconds of fire.

- Jig
Title: Dispersion comparison
Post by: Citabria on December 16, 2000, 02:00:00 AM
p38 and f4u dispersion patterns got mixed up along with the turn rates  (http://bbs.hitechcreations.com/smf/Smileys/default/biggrin.gif)
Title: Dispersion comparison
Post by: funked on December 16, 2000, 02:10:00 AM
Nice job Jig.  Not very scientific but it's the best we've got.  Thanks for doing it.

Cit, do you get different figures than Niklas for sustained turn rates?  His tests at sea level show the P-38L performing significantly better than the rest of the US planes. http://bbs.hitechcreations.com/smf/Smileys/default/Forum9/HTML/000799.html (http://bbs.hitechcreations.com/smf/Smileys/default/Forum9/HTML/000799.html)
Title: Dispersion comparison
Post by: Karnak on December 16, 2000, 02:39:00 AM
Interesting.  I wonder why the F4U is so tight?  I wonder if that is an advantage or disadvantage for long range, spray and pray, shooting?

Jigster,
Could you add the N1K2-J into the fold?

Thanks

Sisu
-Karnak
Title: Dispersion comparison
Post by: Jigster on December 16, 2000, 03:00:00 AM
I'll put the N1K2, Yak and La5 in tomorrow.

- Jig

PS Given the density of shells in that circle, if you do get within it there's a very high chance you'll take a hit (or several) even at range.

It's kinda arbitrary right now because of the change coming in 1.05
Title: Dispersion comparison
Post by: StSanta on December 16, 2000, 05:24:00 AM
Heh, that would explain the f4u lethality a bit.

Notice that the 190 is worst. Anti LW conspiracy, I tell ya!

 (http://bbs.hitechcreations.com/smf/Smileys/default/biggrin.gif).



------------------
StSanta
9./JG 54 "Grünherz"
(http://www.geocities.com/nirfurian/stSanta.jpg)
Title: Dispersion comparison
Post by: danish on December 16, 2000, 05:51:00 AM
Interesting.
Jigster: care to do the G10 without gondolas, and
the Yak as well?

danish

[This message has been edited by danish (edited 12-16-2000).]

[This message has been edited by danish (edited 12-16-2000).]
Title: Dispersion comparison
Post by: juzz on December 16, 2000, 09:17:00 AM
What convergence settings were used on the a/c?
Title: Dispersion comparison
Post by: Andy Bush on December 16, 2000, 10:53:00 AM
I'm a little confused with all of this...or maybe I'm not seeing the point.

Dispersion, by itself, has little to do with convergence/harmonization. It is a measure of percentage of impacts as a function of angle (usually in mils)...not distance or size. For example, a gun might have a dispersion of 80% within a 5 mil circle, meaning 80% of rounds fired impact within a 5 mil diameter circle. This is for ANY range within reason.

I don't claim to have spent hours on the subject, but I've looked at the a/c using one of the custom sights...

 (http://www.doitnow.com/~alfakilo/11.jpg)

...and it seems to me that all wing guns have pretty much the same dispersion...somewhere around plus/minus one tick mark from the center pipper.

My thought is that the size of this dispersion is of generous size...which is a nice way of saying it looks awfully big!

Please note that firing a long burst and then watching the resulting tracer paths is not dispersion!  

Andy
Title: Dispersion comparison
Post by: Jigster on December 16, 2000, 03:23:00 PM
I used 350yrds on each plane. All this basically shows is how far a round can stray from the convergence setting through the length of this shell's life in AH. Some stay very dense (F4U-1C, Spit, G10) and others have no density at all (P-38, FW).

All the guns move back in forth across the gunsight during fire (I assume this recoil and other gun effects) but on some planes the density at a given point in time is drastically different. The 1C keeps a very uniform pattern, where as the Typhoon is much like a scatter gun, covering a much larger area with smae approx. number of shells.

Note the smoke from the gun barrels, they are the only good indicator of the shell flight path once it leaves the barrel. The left, inner cannon on the Typhoon is a good example...the tracer smoke comes so far right it could be normal 200 or 150 yrds convergence setting, where as the rest of the shells follow the 350 yrds convergence line.

Again, this isn't very scientific but there's really no other way to measure it without a virtual gun range  (http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif)

- Jig
Title: Dispersion comparison
Post by: Yeager on December 16, 2000, 04:14:00 PM
Dont get me started!

Yeager
Title: Dispersion comparison
Post by: RAM on December 16, 2000, 04:18:00 PM
I've seen quite many times planes crossing my sights with me firing and getting no hits.

Fw190's guns' dispersion is simply insane.
Title: Dispersion comparison
Post by: GRUNHERZ on December 16, 2000, 04:21:00 PM
Hi

HTC you guys cant ignore this stuff anymore what the hell is your deal with the chog anyway? Cmon havent you guys seen enough evidence yet? Sorry but you cant keep ignoring this for much longer? Plese post anything on the chog gun issue, even if its just telling im full of toejam and shoud shut up  (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif), but please post something, as long as it shows that you guys care and arent just ignoring our ever growing concern over the chog gun issue.  Please

thanks GRUNHERZ
Title: Dispersion comparison
Post by: SOB on December 16, 2000, 08:08:00 PM
None of this makes a whole hell of a lot of difference since bullet dispersion is being changed across the board in 1.05.  How 'bout you wait until then, and squeak about that gunnery model     (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)

   
Quote
Posted by Pyro in http://bbs.hitechcreations.com/smf/Smileys/default/Forum9/HTML/001063.html (http://bbs.hitechcreations.com/smf/Smileys/default/Forum9/HTML/001063.html)
We also made a change to bullet dispersion to make them weighted towards the center of the cone of fire.


SOB


[This message has been edited by SOB (edited 12-16-2000).]
Title: Dispersion comparison
Post by: Jigster on December 16, 2000, 08:16:00 PM
Next time the disclaimers get bold tags, sigh.

Btw the FW actually has about the same density of the 1C up to 300 yards. Past that, however, they go everywhere.

This information will probably be useless once 1.05 comes so hold your comments till then.
Title: Dispersion comparison
Post by: funked on December 16, 2000, 08:17:00 PM
Grunherz you're full of toejam and shut up!

 (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)

You asked for it!!!   (http://bbs.hitechcreations.com/smf/Smileys/default/biggrin.gif)
Title: Dispersion comparison
Post by: RAM on December 16, 2000, 08:21:00 PM
 
Quote
Originally posted by SOB:
None of this makes a whole hell of a lot of difference since bullet dispersion is being changed across the board in 1.05.  How 'bout you wait until then, and squeak about that gunnery model       (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)

Pyro's post dont say they are fixing **some** guns. Seems they are "fixing" ALL guns.

So those circles will have half the radius as they have now. The problem will still be there as the problem right now is not big dispersion in ALL guns, but big dispersion of some planes' guns compared with others...

Even more, the Chog problem may be bigger. From having turbolasers they will move to have Photon Torpedoes.

Damn it, SOB, the other day I downloaded one sight there was in the Training forum that required to put the head higher in the cockpit, set the head position to see the bullets crossing the center dot and save it there.

I have that sight now as default in most planes...in P51 I set the head position in 10 seconds, in F4U more or less the same, P38 took longer, Spit longer...

In the 190s I AM STILL TRYING TO FIGURE WHERE TO SAVE THE HEAD POSITION AS I DONT SEE A PATTERN ON THE SMOKE TRAILS!!

It feels like firing a shotgun. No kidding that just 20 minutes ago a Spitfire crossed twice my bullet stream and he got no hits...again. (With my old sight, and default head position)


Jig, 300yard convergence here for all the cannons. Tried to set the head for the A5 with 2x20mm.

I am still trying to figure where to put the head as some rounds go higher, some lower, some more higher, some less higher, some more lower...etc.

I could set it roughly in the middle of the "Pattern", but I chose to set my old gunsite. At least that one sets the dot in the middle, and I can *imagine* that some rounds will go there.

[This message has been edited by RAM (edited 12-16-2000).]
Title: Dispersion comparison
Post by: SOB on December 16, 2000, 08:47:00 PM
   
Quote
Originally posted by RAM:
So those circles will have half the radius as they have now. The problem will still be there as the problem right now is not big dispersion in ALL guns, but big dispersion of some planes' guns compared with others...

My point is, they're changing the dispersion, and you don't know that what you stated above will be the case.  The new change could completely alieviate the problem.  Perhaps the current problem (if there is one...i wouldn't know either way) is caused by the differences in the way the different ammos are modeled...like ammo weight, muzzle velocity, etc, combined with the fact that there's currently a random dispersion.

Anyhow, just saying the gunnery is changing, and your problem may be fixed with it.


SOB

BTW...Jig, my responce wasn't to you  (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)

[This message has been edited by SOB (edited 12-16-2000).]
Title: Dispersion comparison
Post by: funked on December 17, 2000, 03:35:00 AM
 
Quote
So those circles will have half the radius as they have now.

Nope.  Currently the dispersion is truly random.  Each shot has equal likelihood of landing anywhere "in the circle".  Pyro said they are going to a "center-weighted" dispersion which means the same circle size, but shots are more likely to land near the center of the circle.
Title: Dispersion comparison
Post by: fats on December 17, 2000, 03:04:00 PM
--- funked ----
Pyro said they are going to a "center-weighted"
--- end ---


What causes dispersion? If it's mostly the gun barrel vibrating then center-weighed seems funny to me. The barrel will spend most time at or near the extreme positions and will spend the least time near the center.

That's prolly too simplified guesswork to make any difference.


// fats

Title: Dispersion comparison
Post by: Fatty on December 17, 2000, 04:27:00 PM
Jigster (or anyone else) I posted this in the other thread, putting it here too.  I think for true accuracy you need to have some sort of backstop so you're not trying to judge what tracers to draw the circles on, you can look at hit marks.  Should be possible if someone made a custom terrain with a cliff wall at the end of a runway (someone with more patience than me).
Title: Dispersion comparison
Post by: Jekyll on December 17, 2000, 05:00:00 PM
Fats, actually the opposite is true.  The dispersion of the rounds from the true gun barrel line should be a normal distribution both vertically and horizontally.  With this kind of distribution the greatest concentration of rounds should be towards the centre of the GBL with a decreasing percentage of rounds as you move out to the extremities.

It sure shouldnt be a simple random distribution.

Oh and funked... you fly the Spitfire/Hog combination a LOT, don't you   (http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif)


[This message has been edited by Jekyll (edited 12-17-2000).]

[This message has been edited by Jekyll (edited 12-17-2000).]
Title: Dispersion comparison
Post by: bolillo_loco on December 17, 2000, 05:24:00 PM
does it supprise you that the corsair is the best, even better than planes that have nose armament and no convergence.
Title: Dispersion comparison
Post by: fats on December 17, 2000, 09:27:00 PM
Jekyll,


The frequency that the barrel returns to center is somewhat in sync with the ROF not to cause the bullets to concentrate on the outter rims?

I guess my theory would have been true if the bullets were fired at random interval over a period of time. But since the fact that a bullet is fired causes the barrel to move in the first place it doesn't quite apply...

// fats
Title: Dispersion comparison
Post by: funked on December 17, 2000, 09:43:00 PM
Jekyll I shoot down a lot of hogs in my Spits, Tiffies, and Jugs.   (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
Title: Dispersion comparison
Post by: Andy Bush on December 17, 2000, 09:45:00 PM
Guys...I think you are over-playing this barrel movement thing. Projectile ballistics is also a major consideration, as is barrel wear.

In any case, let's all remember this is a game...something to be played for fun. Regardless of which version, AH is very successful at what we all come here to find...fun!

For those that want to learn the finer points, here's my suggestion. Go to college and graduate. Then go to military pilot training. Do well enough to get a fighter. Then make it thru that training. Then do well enough in your first 3-5 years to earn your squadron's recommendation for Fighter Weapons School. Finish that course, if you can...it will be a tougher academic drill than anything you had in college and far more demanding (and dangerous) flying than you ever imagined.

Then...and only then...are you qualified to get into the nuts and bolts of this.

Many folks here talk about realism. What I just described is about as real as it gets. Anything else is just bartalk and BS.

Andy
Title: Dispersion comparison
Post by: Jigster on December 17, 2000, 11:27:00 PM
deleted, prolly read more into that then was intended.

[This message has been edited by Jigster (edited 12-17-2000).]
Title: Dispersion comparison
Post by: Toad on December 18, 2000, 01:43:00 AM
Andy, if we ever meet remind me that the first six drinks are on me.    (http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif)

Fatty, I would LOVE a terrain that had a backstop at the end of the runway with range markers at the side from 100 to 500 yards. What a Great idea! You could really tune a gunsite/conversion combo then.

[This message has been edited by Toad (edited 12-18-2000).]
Title: Dispersion comparison
Post by: Andy Bush on December 18, 2000, 07:12:00 AM
Jigster

You may have...and I apologize. On subsequent reading, it sounds a bit harsher than I intended.

The enthusiasm in these forums mirrors so well the atmosphere that we see in the MA. Where else can anyone find so much fun (and bang for the buck) than with AH? I'm hard pressed to think of anything. (Except perhaps the O'Club fighter bar on a Friday nite...but that's another story...!!)

On the other hand, sometimes a discussion here seems to stray away from that fun...and into technical areas that have little to do with our enjoyment of this game. My intent was to herd folks back in the 'fun' direction and away from pointless issues that ultimately contribute little to what we all come here for.

Your cautionary note is appreciated.

Andy
Title: Dispersion comparison
Post by: fats on December 18, 2000, 11:00:00 AM
I am glad Andy Bush is here to moderate the conversation. By his rules you are not allowed to ask a question unless you know the answer.


// fats
Title: Dispersion comparison
Post by: Jekyll on December 21, 2000, 02:41:00 AM
Andy, with all due respect, whatever makes you think that these forums are designed for 'fun'?

Most of the posts I take the time to read are discussions of real-life issues.  There's probably a heap of guys in here who would love to understand the issues involved in bullet dispersion etc.

Being told that these weighty real-life issues are far beyond our capacity to understand as mere mortals is a bit over the top, don't you think?

Or do you think someone should not have an interest in politics unless they hold a Doctorate in Political Science?  (http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif)

[This message has been edited by Jekyll (edited 12-21-2000).]
Title: Dispersion comparison
Post by: Torque on December 21, 2000, 04:52:00 AM
I'm with fatty on this (no offense Jiggy) One might as well grab a handful of marbles and throw them in the air and draw a circle.The ROF and gravity play a big part, since the AC are on the ground and are not parallel to the gravitational forces all result will differ. I don't know but do all AC while on ground have the same incline? The distance from center of fuselage to gun placement will change things also. The best I can think of Jiggy is to go to an HQ building have a friend with you, let him park at a distance from HQ to give you a reference point. Land at that point and use HQ building to judge dispersion. Otherwise anyone could draw circles around what they think is dispersion and what is not. Also is it not better to set conv to max distance?

Maybe HTC will give us an aiming mount like the did in real life to set conv. That would stop the ranting anyhow.

<shrug>



[This message has been edited by Torque (edited 12-21-2000).]
Title: Dispersion comparison
Post by: Jigster on December 21, 2000, 05:21:00 AM
 
Quote
Originally posted by Torque:


Maybe HTC will give us an aiming mount like the did in real life to set conv. That would stop the ranting anyhow.


B]

If they don't, I will. I just haven't had time to measure out a gun range yet.

I was messin with some trail stuff and found out the HVARs have a range @ roughly 8 runway lengths  (http://bbs.hitechcreations.com/smf/Smileys/default/eek.gif)

Title: Dispersion comparison
Post by: sourkraut on December 21, 2000, 03:29:00 PM
Wow. I think I've just read one of the most arrogant posts ever on UBB.... <much obnoxious content deleted>... I think someone owes an apology to this community.
Sour
Title: Dispersion comparison
Post by: Andy Bush on December 22, 2000, 04:05:00 PM
Jekyll

Whoa!! I think I may have said something the wrong way!

I meant the sim was for 'fun'...but there's no reason why contributions here can't be fun too. It is for me. I'm always amazed at the enthusiasm and interest shown in the various threads that come along.

>>Being told that these weighty real-life issues are far beyond our capacity to understand as mere mortals is a bit over the top, don't you think?<<

It is a bit 'over the top' and it was not my intent to say or imply such an opinion. Just the opposite, in fact. I like to join in on discussions of RL topics...I bring my RL experience and hope that some may find it useful. If I said something condescending, I apologize.

Let me try it a different way. Some RL topics don't lend themselves to '25 words or less' answers. Some may even merit a doctoral dissertation! Consequently, coming up with info that is both technically correct and, at the same time, applicable to the game is sometimes tough. Add to this the unfortunate times when well-meaning folks inadvertently murky up the water with less than precise info...we could end up with confusion...and that would not be good!

What I was suggesting was that there may be a point past which the discussion loses much of its value. Perhaps I was wrong.

Andy