Aces High Bulletin Board

Help and Support Forums => Help and Training => Topic started by: Ten60 on July 10, 2012, 07:39:31 PM

Title: Rate of drop.
Post by: Ten60 on July 10, 2012, 07:39:31 PM: I'm looking to see if anyone out there has the information on the specific round drop rate's that Ah uses.

I'm doing a convergence study on 50 cal rounds in a specific ride. I am interested to find some ballistic data that would help me to account for the drop rate as well as time.

I've found some resources that have this info, but their accuracy is dependent on the the number of grains, barrel length, and also at their zero'd distance.

I have a feeling that most of this will amount to a fairly negligible +/- error, but I'm just trying to be thorough.
Title: Re: Rate of drop.
Post by: titanic3 on July 10, 2012, 08:49:36 PM: I think bustr already did a data chart on this.
Title: Re: Rate of drop.
Post by: nrshida on July 11, 2012, 01:44:48 AM: Yes, it is 32.2 ft/s/s.
Title: Re: Rate of drop.
Post by: Rob52240 on July 11, 2012, 03:05:27 AM: Quote from: nrshida on July 11, 2012, 01:44:48 AM
Yes, it is 32.2 ft/s/s.

Doesn't everything drop at 32.2 ft/s/s?
Title: Re: Rate of drop.
Post by: nrshida on July 11, 2012, 03:14:42 AM: On Earth, yes.
Title: Re: Rate of drop.
Post by: nrshida on July 11, 2012, 03:19:11 AM: Sorry, I am particularly irritated by idiots today, which of course Ten60 might not be.

The better question Ten60, is how far the bullet travels while that constant is applied to it.
Title: Re: Rate of drop.
Post by: Rob52240 on July 11, 2012, 04:02:17 AM: As a former squaddie I'll vouch that he is no idiot.
Title: Re: Rate of drop.
Post by: FLS on July 11, 2012, 04:42:04 AM: Quote from: Ten60 on July 10, 2012, 07:39:31 PM
I'm looking to see if anyone out there has the information on the specific round drop rate's that Ah uses.

I'm doing a convergence study on 50 cal rounds in a specific ride. I am interested to find some ballistic data that would help me to account for the drop rate as well as time.

I've found some resources that have this info, but their accuracy is dependent on the the number of grains, barrel length, and also at their zero'd distance.

I have a feeling that most of this will amount to a fairly negligible +/- error, but I'm just trying to be thorough.

Have you used the .target command at different ranges?
Title: Re: Rate of drop.
Post by: Rob52240 on July 11, 2012, 04:45:29 AM: Quote from: FLS on July 11, 2012, 04:42:04 AM
Have you used the .target command at different ranges?

Good idea. But what are the physical dimensions of the target in game?
Title: Re: Rate of drop.
Post by: Ten60 on July 11, 2012, 08:29:25 AM: Quote from: Rob52240 on July 11, 2012, 04:02:17 AM
As a former squaddie I'll vouch that he is no idiot.
<S> Thank you sir.

To answer your sarcasm nsshida... I'm actually rather intelligent. What exactly I'm trying to do its find the convergence on a specific plane (had to research the exact gun positions...) where the path stays inside a 4 foot box (2 feet to left and right of the center line of the target plane) for the maximum amount of time. Part of the calculations have included the time of flight and how many feet that adds to the shot, i.e a 400 yard shot has a flight time of .482 seconds. During that flight a plane going 300mph will travel an additional 71 yards.

That being said, I developed some graphic line formulas where I can see the spreads and determine where the converg should be set. Also taking into account longer shots (since a converg of 200 would make an 800 yard shot very very difficult)

So where is this going if I've found that? I'm thinking of writing a program that shows the exact trajectories including drop. This way I can create a target box and find a good fit for the convergence.

But thanks for your help. :salute
Quote from: nrshida on July 11, 2012, 03:19:11 AM
The better question Ten60, is how far the bullet travels while that constant is applied to it.
What alt was the round fired at? Truthfully I am only interested in the first 1,000 yards, thus muzzle velocity and energy have a great impact on the true number, although the variance will probably only be less than a foot at the most.
Title: Re: Rate of drop.
Post by: nrshida on July 11, 2012, 10:04:31 AM: Quote from: Ten60 on July 11, 2012, 08:29:25 AM
To answer your sarcasm nsshida...

That was not sarcasm, it was terse response, which I later explained was due to my contact today with other idiots. If your reading and comprehension skills were commensurate with your intelligence then you would know this. There, now that was sarcasm.

Your calculation can be facilitated through a brief study of external ballistics, and finding the muzzle velocity & ballistic coefficient for your chosen projectile. There are lesser factors too if you want to go into exhaustive detail. For a popular round like that one there are probably already ballistic tables available. I performed this exercise myself for the Japanese Ho-5 20-mm and additionally calculated a table of speeds of aircraft in fuselage lengths per second, but ultimately gunnery in Aces High is best learned by some small theoretical study and then lots of practical application.

If you are trying to find your ideal convergence for a favourite aircraft then it depends greatly on the kind of shots you take, imho.
Title: Re: Rate of drop.
Post by: Ten60 on July 11, 2012, 01:25:18 PM: Quote from: nrshida on July 11, 2012, 10:04:31 AM
That was not sarcasm, it was terse response, which I later explained was due to my contact today with other idiots. If your reading and comprehension skills were commensurate with your intelligence then you would know this. There, now that was sarcasm.

Your calculation can be facilitated through a brief study of external ballistics, and finding the muzzle velocity & ballistic coefficient for your chosen projectile.
You're cute when you try to be cool.

Im aware of what all you've said, but they aren't answers to my questions considering the 50 cal round has been made from ~650 grains up to ~800 grains. This alters the drop rate, which was my initial question.

:airplane:
Title: Re: Rate of drop.
Post by: Skuzzy on July 11, 2012, 01:37:36 PM: Every round in Aces High is modeled using the historical information about the round (mass/weight) and the gun it is fired from (velocity). It is physics driven and every round is modeled.

There is also a certain amount of gunshake modeled, which causes some drift of every round fired. Some are worse (wing mounted guns) than others (cowl mounted guns).

Do not ask me about specific data for any given round as I have reached the pinnacle of my expertise, with this post, in this particular realm.
Title: Re: Rate of drop.
Post by: nrshida on July 11, 2012, 02:12:30 PM: Quote from: Ten60 on July 11, 2012, 01:25:18 PM
You're cute when you try to be cool.

Im aware of what all you've said, but they aren't answers to my questions considering the 50 cal round has been made from ~650 grains up to ~800 grains. This alters the drop rate, which was my initial question.

:airplane:

I thought you said you were: 'rather intelligent'?

No, the weight of the projectile does not alter the drop rate. The drop rate is a constant as I explained above. Ignoring the detailed stuff (which is probably a good idea), what you are trying to calculate is how far the projectile has travelled over time. With this you can plot a roughly parabolic curve which is a consequence of the combination of deceleration and the application of 1G in a downward direction: 32.2 ft/s/s.
Title: Re: Rate of drop.
Post by: Ten60 on July 11, 2012, 03:14:01 PM: Thank you Skuzzy, my question is answered.

Nrshida. While your constant 32.2 f/s is the rate, the weight does matter.

A 647 grain round is fired at approx 3,044 ft/s.
A 800 grain round is fired at approx 2,895 ft/s.

The 647 grain round drops 32.2 feet after the second just like the 800 grain one, AS you stated...

The problem is, after 400 yards of flight the 647 grain round falls only 4.23 feet (because at 3,044 f/s the round only takes .1314 second to fly, then multiplied by the constant) and the 800 grain round falls 4.45 feet (2,895 ft/s) it does matter. Like I also said in an earlier post... The difference will probably be negligible. Of course the rate of velocity decay on the bullet due to drag and the heavier round's ability to compensate that drag with its higher ft/pds energy isn't included with this either, but again likely negligible.
Title: Re: Rate of drop.
Post by: nrshida on July 11, 2012, 03:25:31 PM: Quote from: Ten60 on July 11, 2012, 03:14:01 PM
Nrshida. While your constant 32.2 f/s is the rate, the weight does matter.

Yes for muzzle velocity, deceleration and the energy it imparts in the terminal ballistic stage. Once you have accepted the drop is a constant it all clicks into place.

For the shooting, just learn the flightpath of the round which is fairly predictable and the required lead, I have a manual somewhere hereabouts if you need help with that.
Title: Re: Rate of drop.
Post by: Ten60 on July 11, 2012, 03:37:18 PM: Quote from: nrshida on July 11, 2012, 03:25:31 PM
For the shooting, just learn the flightpath of the round which is fairly predictable and the required lead, I have a manual somewhere hereabouts if you need help with that.
There isn't a manual long enough to make me better at that. I'm merely trying to develop an optimized convergence.
Title: Re: Rate of drop.
Post by: FLS on July 11, 2012, 03:44:31 PM: Quote from: Rob52240 on July 11, 2012, 04:45:29 AM
Good idea. But what are the physical dimensions of the target in game?

The inner circle looks like a 10 ft radius. The target command is the easy way to see the effects of convergence at different ranges and you have the bonus of also seeing the gun dispersion.
Title: Re: Rate of drop.
Post by: nrshida on July 11, 2012, 03:59:19 PM: Here Ten60, read this:-

(http://i1114.photobucket.com/albums/k526/rwrk2/BagtheHunCover.jpg) (http://www.4shared.com/document/SSRZ0ds3/Bag_the_Hun__RAF_Gunnery_Manua.html)

...and watch this...

http://www.youtube.com/watch?v=zsIz2bIBLwM (http://www.youtube.com/watch?v=zsIz2bIBLwM)
Title: Re: Rate of drop.
Post by: bustr on July 12, 2012, 06:03:08 PM: Don't forget drop compensation.

What you are looking for in the game is how to use your gunsight when you boil all of this down. I used to think all of the physics and math you are about to embark on would give me the "A HA" moment of clarity into gunnery in Aces High. It will hone your perceptions to understanding the process without a doubt.

But, it won't substituit for practicing gunnery and understanding the relationship of your bullet streams to your Reticle as affected by physical forces. The British cartoon gunnery manual "Bag the Hun" does but, as a cartoon becasue they learned in WW2 we learn visualy\tactiley. Even the germans with their cartoon manual "Schiessfibel" understood this.

Both Manuals: http://dog.beckament.net/2011/03/31/wwii-air-combat.html

If you follow the math and programing you will learn more about ballistics than you ever wanted to. But, that is not gunnery. You learn gunnery by pulling a trigger. - sight picture - post and pumpkin - whites of their eyes - can't make omlettes with breaking some eggs -

Here is a challenge that will teach you much of what you are really looking for. This will turn into a wall of text and data, so be warned.
-------------------------------------

You will be constructing two gunsights. One to collect data and one to use the data to reap cons. Hitech has made it possible to build gunsights so they are Mil correct to our pilots FoV and gauging size at distance. This means you can study the manuals "Bag the Hun" or "Schiessfibel" and they will work in the game.

A 512x512 bitmap will result in 1Mil = 2Pixel.

Gunsights:

Open your favorite art program.

Making a 100Mil Ring and dot gunsight with drop comp line.

1. - Open a new 512x512 art sheet and save it as an 8bit bitmap. Name it GunS1.bmp.
2. - Save As a copy name it GunS2.bmp.
3. - In both fill the background with black.
4. - In both create a 3 pixel wide orange circle starting your pull from (156, 156) ending at (356, 356).
5. - In GunS1 at (256, 256) paint an 11 pixel dia orange dot.
6. - In GunS1 at line 284 use a line tool and pull a 1 pixel orange line from ring edge to ring edge.
7. - Save GunS1 you now have a 100Mil ring and dot gunsight with a drop comp line for wing mounted guns.
8. - For nose mounted guns like the La7, 109, Yak and even the 190's becasue the cannons are so close to the fuslage. Draw the comp line at 278. In my gunsights I've further reduced these lines to hash marks with 5 pixel spaces. If you run a blur tool over this gunsight to smooth the edges. Zoom in and reduce the ghost line back down to 1 pixel wide.

Making a data Collection gunsight to use with the Offline Target.

1. - Open GunS2.bmp.
2. - Pull 2 lines 1 pixel width in CYAN color as a bisecting cross centerd at (256, 256).
3. - Mirror these two lines in orange 20 pixel above and below the horizontal and 20 pixel left and right of the vertical.
4. - Horizontal and vertical at every 20 pixel create a 1 pixel (orange) line connection between the orange parallel lines making ladders.
5. - Now at every 10 pixel in between these draw 1 pixel wide lines (cyan) 11 pixel wide. You are creating a hash grid.
6. - You should have a hash grid cross centerd in a 100Mil dia circle with units of separation demarkiing 10Mil and 5Mil in orange and cyan.

The 512x512 format requires you include in your sights directory a text file with the same "name.mil" to support the "name.bmp" reticle displaying correctly in your gunsight.

For GunS1.bmp create a GunS1.mil file with the number 256 saved in it.
For GunS2.bmp create a GunS2.mil file with the number 256 saved in it.

I have found the best way to create the mil file and have AH parse it properly is the folowing.

1. - Open notepad. Save a new text file with 256 in it as "GunS1.mil.txt"
2. - In file manager highlight the file and do a rename by removing the ".txt" reducing it to "GunS1.mil"
3. - Place both the GunS1.bmp & GunS1.mil in your Sights directory and the gunsight will display correctly when you spawn your fighter. A 100Mil ring just fills the hight of the K14 gunsight reflector plate in the P51D.
4. - Repeat with GunS2.
---------------------------------------

How to use these gunsights to compliment each other.

The Guns2 gunsight is a Mil gauge collection tool used in conjunction with the offline target. You fly your aircraft due north autoleved and pull up the target at any distance out to 5k in .5 yard incraments starting at 1.0 yards. This how I created the speed chart to make every fighter in the game fly in an attiude that mimics placing the fighter up leveled on a static stand able to shoot out to 100 yards. Including it in this post exceeded my 1000 work limit.

Data collection using the P51D and Guns2.

1. - Set all guns to 300 convergence for this test and select Guns2 from the gunsights app. 25% fuel.
2. - Use any offline airfeild that lets you fly North over water for 5 or 6 sectors.
3. - Spawn and takoff, climb to 1000 feet flying due north. Set speed for the P51D to 285 True Airspeed. (.SPEED DesiredMPH)
4. - Open the E6b and make sure True Airspeed is 285.
5. - You can test this by (.Target 3) and see that the center of the spinner is centered into the center of the target.
6. - Set arena time to (.time 01:00). It's easier to see the target and reticle lines on Full Zoom.
7. - Set the target out in 25, 50, 100 yard incraments from 100 to 600 and on full zoom shoot while looking at the patterning. Notice the relative relationship of the reticle center to the pattern at each distance. Think about this relative to the drop compensation line you will test next.

Using the drop compensation line in Gun1.

1. - Offline using your P51d and convergence still at 300, 25% fuel.
2. - Set your arena time back to noon. (.time 12:00).
3. - Choose Gun1 from the gunsight app.
4. - Spawn and climb up to 3k into the drone circle.
5. - Starting at 400 back of a drone goto zoom and place the drop comp line inline with the drone's wings.
6. - Hold off the correct lead into the circle and fire. Watch your tracers arch up and drop into the drone. Adjust as needed.
7. - Repeat at 200, adjust as needed. This works even at 600 adjust lead and elevation as needed.
8. - Enable the Lead Computing gunsight and repeat this test. Note the relative position of the drop comp line as you place the center circle on the green crosses.
9. If you made an additional gunsight with the 278 line try the same with your La's, Yaks, 109's and 190's. Placing the two lines in a GunS1 will become confusing.

This is not a point a click solution. It is a constant reference guide line to help you start from a good sight picture knowing what the level drop compensation is. If you download and read "Bag the Hun" you will recognise what this gunsight is guiding you to as your sight picture. GunS1 line 284 is for all wing mounted guns, MG or cannon mounted outboard of the landing gear. GunS1 line 278 is for nose and hood guns. Cannons closer into the fuslage act like hood and nose mounted guns in their horizontal ballistics and convergence to the hood mounted MG.

Note: By adding a 120Mil single pixel wide ghost circle to GunS1 284, you give yourself the 30 degree holdoff from "Bag the Hun".
---------------------------------------

Units of Mil

1Mil @ 50yds = 1.7 inches
1Mil @ 100yds = 3.6 inches
1Mil @ 150yds = 5 inches
1Mil @ 200yds = 7 inches
1Mil @ 250yds = 9 inches
1Mil @ 300yds = 11 inches
1Mil @ 350yds = 12.5 inches
1Mil @ 400yds = 14 inches
1Mil @ 450yds = 16 inches
1Mil @ 500yds = 17.5 inches
1Mil @ 550yds = 19 inches
1Mil @ 600yds = 20 inches
1Mil @ 650yds = 23 inches
1Mil @ 1000yds= 36 inches
Title: Re: Rate of drop.
Post by: bustr on July 13, 2012, 04:38:00 PM: Today is another day...

List of tested aircraft cruise speed.

United States

Aircraft----Speed
F4F--------250 true
F4U1-------260 true
F4U1A------260 true
F4U1C------260 true
F4U1D------260 true
F4U-4------280 true
F6F-5------260 true
FM2--------225 true
P38G-------250 true
P38J-------250 true
P38L-------260 true
P39D-------250 true <--37mm T9 cannon Motor Cannon
P39Q-------250 true <--37mm T9 cannon Motor Cannon
P40C-------220 true
P40E-------240 true
P40F-------245 true
P40N-------250 true
P47D11-----290 true
P47D25-----290 true
P47D40-----290 true
P47M-------290 true
P47N-------290 true
P51B-------283 true
P51D-------285 true
----------------------------------------------------------------
Great Britain

Aircraft----Speed
HurriI-----210 true
HurriIIC---220 true
SpitI------285 true
SpitIIc----290 true
SpitV------280 true
SpitVIII---255 true
SpitIX-----250 true
SpitXIV----260 true
SpitXVI----260 true
MossiVI----255 true
TempestV---280 true
TyphoonIb--270 true
----------------------------------------------------------------
Germany

Aircraft----Speed
Bf109E4----240 true
Bf109F4----240 true <--Mg151/20 Motor Cannon
Bf109G2----280 true <--Mg151/20 Motor Cannon
Bf109G6----280 ture <--Mg151/20 Motor Cannon
Bf109G14---280 true <--Mg151/20 Motor Cannon
Bf109G14---290 true <--Mk108 30 Motor Cannon
Bf109K4----290 true <--Mk108 30 Motor Cannon
Bf110C4b---220 true
Bf110G2----250 true
FW190A5----275 true
Fw190A8----280 true
FW190D9----280 true
FW190F8----282 true
Ta152H1----275 true<--Mk108 30 Motor Cannon
Me163------420 true
Me262------300 true
----------------------------------------------------------------
Italy

Aircraft----Speed
C.202------265 true
C.205------295 true
----------------------------------------------------------------
Russia

Aircraft----Speed
I16--------255 true
La5--------275 true
La7--------275 ture
Yak9T------275 true <---NS-37 Motor Cannon
Yak9U------275 true <---ShVAK20 Motor cannon
----------------------------------------------------------------
Finland

Aircraft----Speed
Brewster---230 true
----------------------------------------------------------------
Japan

Aircraft----Speed
A6m2-------210 true
A6m3-------215 true
A6m5-------220 true
Ki61-------255 true
Ki84-------265 true
N1K2-------260 true
Title: Re: Rate of drop.
Post by: Traveler on July 14, 2012, 12:07:58 AM: I have a question,

A 647 grain round is fired at approx 3,044 ft/s.
A 800 grain round is fired at approx 2,895 ft/s.

These two figures are for a static shot, correct? That is the guns are standing still at the time of the shot. Not moving at 300 miles per hour through the air. Is the speed of the gun, added to the speed of the round. If I am sitting still, 0 airspeed and I fire one round the 647 grain round is going to be traveling at 3, 044 feet per second. But if my aircraft is traveling at a ground speed of 300 miles per hour isn’t that speed added to the speed of the round?

thank you in advance.
Title: Re: Rate of drop.
Post by: FLS on July 14, 2012, 07:40:11 AM: That's correct and at altitude the air density is less which reduces the drag.
Title: Re: Rate of drop.
Post by: Ten60 on July 14, 2012, 08:18:02 AM: Quote from: Traveler on July 14, 2012, 12:07:58 AM
I have a question,

A 647 grain round is fired at approx 3,044 ft/s.
A 800 grain round is fired at approx 2,895 ft/s.

These two figures are for a static shot, correct? That is the guns are standing still at the time of the shot. Not moving at 300 miles per hour through the air. Is the speed of the gun, added to the speed of the round. If I am sitting still, 0 airspeed and I fire one round the 647 grain round is going to be traveling at 3, 044 feet per second. But if my aircraft is traveling at a ground speed of 300 miles per hour isn’t that speed added to the speed of the round?

thank you in advance.

This is correct, but remember that the additional speed would be added to either round equally. That would make it's difference balance out (with exception of the drag coefficient that would reduce the speed of the faster round slightly faster). 300 mph=440ft/sec
Title: Re: Rate of drop.
Post by: fuzeman on July 14, 2012, 08:51:46 AM: Quote from: Skuzzy on July 11, 2012, 01:37:36 PM
Every round in Aces High is modeled using the historical information about the round (mass/weight) and the gun it is fired from (velocity). It is physics driven and every round is modeled.

There is also a certain amount of gunshake modeled, which causes some drift of every round fired. Some are worse (wing mounted guns) than others (cowl mounted guns).

Do not ask me about specific data for any given round as I have reached the pinnacle of my expertise, with this post, in this particular realm.

Do you happen to know the average airspeed of an unladen swallow?
Title: Re: Rate of drop.
Post by: Ten60 on July 14, 2012, 09:26:13 AM: The below graph is a convergence from a specific plane in AH. The actual y values are estimated using historical schematics of the plane to judge distance from the center-line of the plane. X values are distance in yards. The red box represents the area when all 6 bullet paths are inside the fuselage area.

(http://i440.photobucket.com/albums/qq124/jerpyro20/graphstudy2.jpg)

Ok so many people are posting gunnery information, which I appreciate, but that is not the topic I was trying to get an answer to. Maybe I wasn't clear enough. I'm doing a "Convergence Study" to find a maximized setting. Above you see what I'm talking about. The blue box represents the fuselage of the target plane. It has a 4 foot wide area, 2 feet from the center-line. The purpose of the study is to find the maximum size of the red box (Where all 6 guns are inside the blue box). Of course by setting the guns to 650 you find the largest naturally, but the spread would be far to wide at 200 to get a decent concentration of firepower.

Some would say, just set it at 200. That's where you should be firing from anyway. Well then a shot at 400 (As was shown in the Hun video) would be futile. This shouldn't be surprising to anyone who understands geometry... Whatever distance is twice your convergence is the distance which the path's are equal to the originating spread.

So this is where the thought came from. At what point is a shot at ~200 still damaging, yet I can also effectively hit someone at ~600?? Well the obvious choice would be 400.

(http://i440.photobucket.com/albums/qq124/jerpyro20/Comparison.jpg)

This is the result of my study. The rounds enter the fuselage zone at 255 yards and exit at 545 when set @ 400. So I started to think, how can I expand this box while leaving the target zone as close to 400 as possible, i.e. Maximize the red box. My green set of lines enters @ 272 and exits @ 603. 17 yards later but stays in the zone for an additional 58 yards, for an extended effective range of 41 yards.

Now, you can all say, "Well they didn't do it in real life so why could this be right?" It's probably not lol... BUT I'm getting closer. Not to mention IRL they didn't really pray and spray from 600 like we do in AH. It's a totally different type of combat.

Now do you guys understand what I'm doing? The reason for asking about the drop factors and weight was so that I could add in a z axis.
Title: Re: Rate of drop.
Post by: shppr01 on July 14, 2012, 11:00:49 AM: Quote from: fuzeman on July 14, 2012, 08:51:46 AM
Do you happen to know the average airspeed of an unladen swallow?

Would that be an African swallow or a European swallow ???
Title: Re: Rate of drop.
Post by: The Fugitive on July 14, 2012, 12:04:35 PM: Quote from: shppr01 on July 14, 2012, 11:00:49 AM
Would that be an African swallow or a European swallow ???

ok, who had 2 hours and 9 minutes in the "African swallow or a European swallow post" pool?
Title: Re: Rate of drop.
Post by: mtnman on July 14, 2012, 12:53:57 PM: Quote from: Ten60 on July 14, 2012, 09:26:13 AM
The below graph is a convergence from a specific plane in AH. The actual y values are estimated using historical schematics of the plane to judge distance from the center-line of the plane. X values are distance in yards. The red box represents the area when all 6 bullet paths are inside the fuselage area.

(http://i440.photobucket.com/albums/qq124/jerpyro20/graphstudy2.jpg)

Ok so many people are posting gunnery information, which I appreciate, but that is not the topic I was trying to get an answer to. Maybe I wasn't clear enough. I'm doing a "Convergence Study" to find a maximized setting. Above you see what I'm talking about. The blue box represents the fuselage of the target plane. It has a 4 foot wide area, 2 feet from the center-line. The purpose of the study is to find the maximum size of the red box (Where all 6 guns are inside the blue box). Of course by setting the guns to 650 you find the largest naturally, but the spread would be far to wide at 200 to get a decent concentration of firepower.

Some would say, just set it at 200. That's where you should be firing from anyway. Well then a shot at 400 (As was shown in the Hun video) would be futile. This shouldn't be surprising to anyone who understands geometry... Whatever distance is twice your convergence is the distance which the path's are equal to the originating spread.

So this is where the thought came from. At what point is a shot at ~200 still damaging, yet I can also effectively hit someone at ~600?? Well the obvious choice would be 400.

(http://i440.photobucket.com/albums/qq124/jerpyro20/Comparison.jpg)

This is the result of my study. The rounds enter the fuselage zone at 255 yards and exit at 545 when set @ 400. So I started to think, how can I expand this box while leaving the target zone as close to 400 as possible, i.e. Maximize the red box. My green set of lines enters @ 272 and exits @ 603. 17 yards later but stays in the zone for an additional 58 yards, for an extended effective range of 41 yards.

Now, you can all say, "Well they didn't do it in real life so why could this be right?" It's probably not lol... BUT I'm getting closer. Not to mention IRL they didn't really pray and spray from 600 like we do in AH. It's a totally different type of combat.

Now do you guys understand what I'm doing? The reason for asking about the drop factors and weight was so that I could add in a z axis.

I did a bunch of testing along these lines a few years back also. I think you're on the right track, but are missing out on a few key points. The 400yd convergence is decent (and maybe even "best") if you're just trying to get some hits on your target, but is definitely not an "optimal" setting if you're more interested in making your MG's as effective as possible.

In AH, there's also an advantage to be gained if you can "know" when a target is at your convergence setting/distance, and are able to fire at that distance.

You may get a longer/deeper "window" with a 400yd convergence setting, but it's very difficult to "know" when your target is at 400yds in game. So while you're able to sprinkle hits on targets across that deep window, you'll only ever hit a plane at convergence distance by luck. This keeps you sprinkling hits on your target, but never really maximizes the effectiveness of your guns. The MG's in AH are not effective when sprinkled across a target, unless you get a lucky hit in on the pilot, etc...

When an icon tells you it's at 400 in AH, it's almost never at 400yds from you. "D400" spans a 200yd distance in AH. "D400" means the target is somewhere between 300 and 499 yards from you.This means that to fire at a target at 400yds (with your convergence set to 400) you need to use a different method to judge distance. That can be done using your retical as a measuring aid, but that also means you need to compensate for every plane type, and every angle those planes could be fired at (amongst all of the other variables of course). That's tough.

However, there are several distances where the icons give you a much better distance reference that can be used to "know" your target is at the proper distance for you to maximize your convergence settings. These distances are the points where one icon switches to the next. This happens at several potentially "useful" distances in AH. It happens for example as the D0 icon switches to the D200 icon at 100yds distance from you. And again at 300yds as the D200 icon switches to the D400 icon (and at 500 yards, and 700 yards).

Looking at those "sweet-spot" distances, you'll be able to utilize that info to it's max if you set your convergence at 100, 300, 500, or 700yards. With wing-mounted guns, 100 is a terrible choice (look at the screenshots from the thread link I'll include). Setting your convergence at 100yards will make you shoot way high on almost any target at "reasonable" ranges. 700 isn't a possible setting in AH, but I think 650 is? The problem with that setting is that it spreads your shots around too wide of an area across all "reasonable" distances (you're back to getting hits again, but not "effective" concentration of MG rounds on target).

That leaves 300 or 500 yard convergences as being potentially "optimal". The first thing I noticed here was that on a 500yd target, my rounds were spread about equally whether I had my convergence set to 300 or 500 (no real advantage with either setting, although this is where I "should" have seen an advantage with a 500yd setting). Most of my firing is done in the D200/D400 range, so it didn't look like it mattered all that much which setting I chose. The effectiveness was the same, I just needed a slightly different aim-point for each setting.

However, with a 300 yard setting I noticed a big difference. 300 convergence at 300 yards is a very effective setting. 500 convergence at 300 isn't as effective/concentrated. Advantage 300... At 500 yards with a 300yd convergence, once again there's not a huge advantage between either setting, but the 500yd convergence never has the concentration the 300 has. Advantage 300 again...

The difference between the two settings is that with a 300yd setting, I can "know" my target is at the most effective range when I fire (an easy example is to come in behind an enemy at D600, and hold your fire as you move into D400, solidify your aim, and fire as the icon switches from D400 to D200; your target is at 300yds, maximizing the effectiveness of your 300yd convergence). In reality, I find 275 to be "best" for me, regardless of the plane I fly. Your rounds are also flying faster at 300 than they are at 500, so once again, advantage 300...

One factor at play here is the modeled-in dispersal of the rounds. Due to this, the further out you set your convergence the less effective your rounds will be. If you set your convergence at 200, and fire at 200, you'll do more damage than you would firing at 400yds with a 400yd convergence. Even though both examples give the "best" effect for each convergence setting, the 400yd convergence causes less concentration, results in more misses, and does less damage. Closer is better, until you reach the point where you're "too" close.

http://bbs.hitechcreations.com/smf/index.php/topic,291146.0.html

This isn't to say that 400 isn't the "best" option. For you it may be. For me (flying F4U predominately) it definitely isn't. Looking best on paper doesn't always equate to best in reality (or the pseudo-reality we play with here). I don't use a "standard" retical either, so that may play a role. I use the smallest "dot" site I can find. I don't really use it to aim with, it's just there as a reference point, and I don't use it to judge distance or lead.
Title: Re: Rate of drop.
Post by: Badboy on July 14, 2012, 01:54:10 PM: Quote from: nrshida on July 11, 2012, 01:44:48 AM
Yes, it is 32.2 ft/s/s.

It's not that simple, the vertical acceleration of a ballistic object varies during the time of flight depending on several factors, if it was always 32.2 ft/s/s there would be no such thing as terminal velocity, when it gets very close to zero ft/s/s.

Badboy
Title: Re: Rate of drop.
Post by: Badboy on July 14, 2012, 01:57:18 PM: Quote from: Rob52240 on July 11, 2012, 03:05:27 AM
Doesn't everything drop at 32.2 ft/s/s?

Nope, that value is only correct if there were no resistance to cause deceleration. The actual value will depend on the drag and the mass of the ballistic object.

Badboy
Title: Re: Rate of drop.
Post by: Badboy on July 14, 2012, 02:06:22 PM: Quote from: nrshida on July 11, 2012, 02:12:30 PM

No, the weight of the projectile does not alter the drop rate. The drop rate is a constant as I explained above.

Not so, the weight does influence the deceleration and the drop rate. Generally speaking if you have two objects with the same shape and size and the same drag, the heavier one will be decelerated less than the lighter one which is partly why heavier projectiles have better ballistics than lighter ones.

Badboy
Title: Re: Rate of drop.
Post by: Badboy on July 14, 2012, 02:42:40 PM: Quote from: Ten60 on July 11, 2012, 03:14:01 PM
The 647 grain round drops 32.2 feet after the second just like the 800 grain one, AS you stated...

Hi Ten60,

You have been led into some false assumptions there, the different weights do have an impact on the drop. Many people believe that things fall due to gravity at the constant rate of 32.2 ft/s/s because they assume that the acceleration will be constant because the force of gravity is constant but that is not true.

Let me explain with some simple math.

Let g = force of gravity
let m = mass of projectile
let a = acceleration of projectile

Now apply Newton's law F = ma

The force on any objectdue to gravity F = mg

So we get mg = ma

where m cancels out and of course a=g

Thus the notion that that the acceleration is constant at g = 32.2ft/s/s

What is wrong with this is that it ignores other important forces. It isn't only gravity at work on a projectile, drag forces play an important part.

For example if we represent the force due to drag with the character d our equation for the force F becomes F = mg - d

Now when we put that into Newton's law we get ma = mg - d

Now if we divide both sides by m to find the acceleration a we get a = g - d/m

Now you see that the acceleration isn't just g, it is less than g by the amount d/m. So the mass, and thus the weight does play an important part in ballistics if drag is included in your thinking.

Hope that helps...

Badboy
Title: Re: Rate of drop.
Post by: JOACH1M on July 14, 2012, 02:55:43 PM: I just point and shoot where they are going to be and I kill them.
Title: Re: Rate of drop.
Post by: bustr on July 14, 2012, 07:18:50 PM: "I just point and shoot where they are going to be and I kill them."

Joachim,

Eventualy everyone figures that out. You are a "natural" air to air shooter like some are natural skeet shooters.

When you are trying to hit people at 400+ it usualy means you are having problems getting the red guys to fight you closer if they don't have freinds versus just you or a superior situational advantage. Then you go through a period of trying to become good at hitting them outside of 300 and fiddeling with convergence to maximise your rounds on target percentages. I've watched everyone in my squad go through this stage in the game over years of playing with them.

Convergence is nice, everyone finds theirs, and Ten60 looks like he's writing a great program that will augment auto level on full zoom shooting at the offline target. Past 300 it's knowing where your rounds are going to be relative to your gunsight picture, along with how much drop compensation at a given range, combined with your relative alt and atitiude, then how much lead to hold off related to G in your turn, or just shooting level at distance. Basic shooting "Dope" translated through your gunsight picture in "Mil" from a moving vehical. The K14 you set your wingspan at distance knob. Held the star on the target 1-2 seconds while the gyros moved the reticle against the G forces in your turn to compensate your hold off and atitiude. No mental calculations or lookup sheets to remember with a static reflector reticle.

Because of that ghost line in my gunsight I hit cons 600-800 becasue I have a known reference point relative to me in a 3D world and know what the dispersion blocks are at range from data collection testing. Dispersion is a bite and just gets worse at range, not your aiming. Past 300 dispersion becomes a major source of impediment to getting enough rounds on target to do the job unless they are running level away from you. You can see it in spades with the MK108 past 150 against the offline target. What is it..14ft dispersion at 200 yards for the Mk108. At least at that range the right hand spin drift is only 8 inches.

I hope Ten60 puts a sub calculation into his program for the amount of hold off of 100Mil rings at distance of a con moving left to right at different speeds for a round type's InitV. It would be a usefull tool for new players to understand why they miss so often on snap shots while just starting out in this game. They shoot way too late and either too low or too high from the atitiude they are in. I made a gunsight that corrected for alot of that. It just had too many static lines to keep track of in the heat of the moment even if I was pulling some fantasic point and click snap shots when I lined up the correct lines.

I came up with the lines after reading a K14 manual and tech description of the theory behind the function realted to zeroing the guns in the P51D for the K14 to achive a maximised shooting pattern at combat distance 200-350. Anything closer fills the screen and in theory you can't miss.

I eventualy went back to using the "Bag the Hun" book's method and a 100Mil ring with most of my conv 300ish becasue it was alot of bother remembering how to use the lines in place of the K14 gyro doing it for me.
Title: Re: Rate of drop.
Post by: nrshida on July 15, 2012, 02:57:20 AM: Quote from: Badboy on July 14, 2012, 02:42:40 PM
You have been led into some false assumptions there,

It was a simplification to illustrate a point. Respectfully Badboy, your model is also a simplification and does not contribute anything practically useful to learning the flight paths of our virtual bullets.

I also tried the calculation approach once, practically however I agree with Joachim and Bustr: people have the potential to develop special 'equipment' to work these things out instinctively (with careful practice).

If you really want to get a feel for shooting take up archery. I apply that experience a lot when shooting 30-mm.

Bag the Hun will help a lot with learning to lead correctly.
Title: Re: Rate of drop.
Post by: Ten60 on July 15, 2012, 06:38:47 AM: Quote from: nrshida on July 15, 2012, 02:57:20 AM

It was a simplification to illustrate a point. Respectfully Badboy, your model is also a simplification and does not contribute anything practically useful to learning the flight paths of our virtual bullets.

I also tried the calculation approach once, practically however I agree with Joachim and Bustr: people have the potential to develop special 'equipment' to work these things out instinctively (with careful practice).

If you really want to get a feel for shooting take up archery. I apply that experience a lot when shooting 30-mm.

Bag the Hun will help a lot with learning to lead correctly.

I guess I'm just gonna give up.

THIS ISN'T A POST ABOUT AIMING!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

I guess trying to be nice about it just hasn't worked. I'll no longer be posting on this thread, thanks to those who helped.
Title: Re: Rate of drop.
Post by: RTHolmes on July 15, 2012, 06:44:02 AM: Quote from: Ten60 on July 14, 2012, 09:26:13 AM
Now do you guys understand what I'm doing?

I do, and its why I set my jug guns staggered so I get a tunnel of bullets a few feet wide (ie. the size of the damage box for most of the crucial parts of the aircraft) which extends 150-200yd either side of the average convergence. works great, which is presumably why they set up 8-gun jugs this way during WWII :aok

edit: btw are you staggering them parallel or crossing streams? I have them parallel (ie. outer guns set furthest out.)
Title: Re: Rate of drop.
Post by: Alky on July 15, 2012, 11:33:13 AM: Quote from: Ten60 on July 11, 2012, 01:25:18 PM
considering the 50 cal round has been made from ~650 grains up to ~800 grains. This alters the drop rate, which was my initial question.

Hmm... how do you convert that to pixels?? :rolleyes:
Title: Re: Rate of drop.
Post by: Badboy on July 15, 2012, 12:30:27 PM: Quote from: Ten60 on July 15, 2012, 06:38:47 AM
I guess I'm just gonna give up.

That would be a shame, because I think I can help. Just hang in there a little longer. There was a thread posted some time ago in which hitech posted enough information to reverse engineer the ballistics for at least one of the AH .50 calibre weapons.

You originally posted:

Quote from: Ten60 on July 10, 2012, 07:39:31 PM
I'm looking to see if anyone out there has the information on the specific round drop rate's that Ah uses.

What happens in AH is that the trajectory of the rounds are determined by a physics model based on the properties of each round and weapon. The model runs everytime you fire your guns and just like the flight model it calculates the position of the round in real time. It may be that at some point drop rates were used to calibrate the model, but if you want to discover the drop rates being used in AH, you don't need the drop rates that AH used to fine tune their model, all you need is ingame data. hitech was kind enough to provide sufficient information in this thread:

http://bbs.hitechcreations.com/smf/index.php/topic,309540.0.html

In that thread the following data was provided:

Quote from: hitech on March 25, 2011, 09:56:56 AM
With the assumption that the bullet does not destabilize , I would think it would given the numbers below.

Alt 25k 45k
Launch Speed 450mph 528mph
Secs to impact 65 97
Horizontal Distance 30858 55107
Plane Dist Traveled 42880 75082
Speed at impact. 444FPS 446FPS

HiTech

Using that information it is possible to calibrate a ballistics model, just like the one used in the game, in order to produce your own drop rates either graphically or in tables.

As it happens I've already done that and graph below shows the trajectory based on my model of a .50 calibre round that matches AH almost exactly, same range, time of flight and speed on impact etc.

(http://www.leonbadboysmith.com/images/Trajectory01.jpg)

That graph isn't helpful by itself, what would be more helpful would be a graph based on the same model, that showed the trajectory, and thus the drop over the sort of ranges we use in the game. The image below uses the same data as the previous one for a convergence at 300yds. The actual trajectory is really very flat, but it looks more curved on the graph because the axis are drawn to different scales.

(http://www.leonbadboysmith.com/images/Trajectory02.jpg)

Is that the kind of information you were looking for?

If you were serious about not posting again, feel free to PM me.

Regards

Badboy