[Coding] Balistics/zeroing [WIP]

[zangoo]

hey i was playing kashan and i was a cobra, so i found a empty command truck opened up on it with my 20mm, it took like 40 rounds. i am thinking that like 5 20mm rounds would disable the truck irl. so to my point, i think that a rework of the ballistics for planes, and attack helis should be thought about.

[Mosquill]

Ok, so i guess there won't be any 3d sights. Jonny do you still have time before your exams?

[KP]

For the barrel/scope distance, will it be good enough if I just find the total weapon length IRL, divide it by the length of the weapon on a picture to get a conversion factor, and then measure the distance between barrel/scope and multiply it by the conversion factor?

[Mosquill]

[quote=""KP"]For the barrel/scope distance, will it be good enough if I just find the total weapon length IRL, divide it by the length of the weapon on a picture to get a conversion factor, and then measure the distance between barrel/scope and multiply it by the conversion factor?[/quote]
[quote="Jonny""]I still have time, I would prefer to use the scope-barrel distance from the models we are using (I am assuming 5cm for all but the SVD in post #2 ATM, I want better values so I will keep stating this).[/quote]
I think I can measure scope-barrel distance using game models, so there shouldn't be any probmlems. Thanks for all your help KP, but I guess there's no need for you to measure the distance.

@Jonny: so what are the priorities?
1.Find out what is changing K
2.Get scope/barrel distances
3.Calculate ballistics
4.Make animations
5.Test
?

We do need to know what's wrong with K right? Or are you going to recalculate it every release?

[KP]

Right-o, I'll keep looking for the BCs.

The M33 .50 projectile used in the M95 and M2 has a BC of 0,34. MV for M2 is 930 m/s; for the M95, it's 854 m/s.

For the AK-74M/AKS-74/other 5.45 AK versions, the BC of the round is 0,168. MV for the AKs (except the AKS-74U)is 900 m/s; for the AKS-74U it is 735 m/s.

[Mosquill]

Right-o, I'll keep looking for the BCs. The M33 .50 projectile used in the M95 and M2 has a BC of 0,34. MV for M2 is 930 m/s; for the M95, it's 854 m/s.

If you'll have any problems finding BC's, then there's no need. I can get the BCs much easier, I already have 2 collections of BC's and few BC calculators. What we really need to know is what kind of bullets should be used. For example is it M118 or M118LR (m14/m24/m40), M118LR is the replacement afaik, but I have no clue how common it is.

1 no, can react to it when it changes.

What do you mean by that?

EDIT:

The M33 .50 projectile used in the M95 and M2 has a BC of 0,34. MV for M2 is 930 m/s; for the M95, it's 854 m/s.

For the AK-74M/AKS-74/other 5.45 AK versions, the BC of the round is 0,168. MV for the AKs (except the AKS-74U)is 900 m/s; for the AKS-74U it is 735 m/s.

Where did you get those BCs? They can't be right.

[zangoo]

should someone make a list of all guns in pr, then next to it, add the bullet, projectile mass, bc, muzzel speed, ect. then the whole thing would be done fast.

[KP]

If you'll have any problems finding BC's, then there's no need. I can get the BCs much easier, I already have 2 collections of BC's and few BC calculators. What we really need to know is what kind of bullets should be used. For example is it M118 or M118LR (m14/m24/m40), M118LR is the replacement afaik, but I have no clue how common it is.

What do you mean by that?

EDIT:
Where did you get those BCs? They can't be right.

Use the M118LR - it's on it's way in and will probably be much more common i a couple of years, when PR takes place.

Got the BCs from the tables on this site, and I presumed them to be correct:

Ballistic Coefficient Tables

[Mosquill]

Use the M118LR - it's on it's way in and will probably be much more common i a couple of years, when PR takes place.

Got the BCs from the tables on this site, and I presumed them to be correct:

Ballistic Coefficient Tables

Most of those BCs aren't correct at all.

This is a list of the manufacturer’s published "G1" ballistic coefficients

"G1" BCs means they were calculated using the original blunt-nosed, flat-based standard projectile drag model designed in the 1870's by Krupp of Germany.

G1 model is not applicable to big variety of modern bullets.
For example (from that table):

Brand/Diameter/Weight/Type/BC
Barnes/0.51/50/Solid-Bore Rider/1.07
Barnes/0.51/750/Solid/1.07
Barnes/0.51/750/Solid/0.766
Barnes/0.51/800/Solid-Bore/Rider/1.095
Hornady/0.51/750/A-MAX/1.05

There are no bullets with >1 BC, it's simply not possible.

I will have to start a version of my spreadsheet on google-something later.

Mosquill:
The important thing is the value of m/k for each bullet, if m is changed as k changes to keep it constant then the tragectory will be the same. This also means that the angles are a one-off thing, it may be a lot of work but once it is finished it will not need to be done again except for new rifles.

Yeah I already figured about m/k by now. The quetion is: are you going to calculate K for every release?

[zangoo]

jonny if you want a real good measurement of k, you will need to use the soflam to measure the real distance between you and the target. also just using a stop watch or some other timer wont work. you will have to use the battlerecorder and slow it down to get a good measurement.

[Mosquill]

Looks like I'm the only one who realizes that we need to know what changes k.

[KP]

OMG, I'm a n00b! :d uh:

Well, I'll keep looking for the data.

[Mosquill]

Sights height for high and mid priority guns (measured on game models)(in cm):

Dragunov SVD:7
Mosin Nagant:8.2
SV98: no model
L86 DMR:8
L115A1:5.1
M40:5.7
M14:5.1
QBU88:8.3
SSG69: no model
M16a4(scope):7
M16a4(iron):6.9
M4:6.3
M249:4.5
L85A2(scope):8.8
L85A2(iron):8.8
Minimi:4.5
L119A1:6.3
QBZ95-scope:13.3
QBZ95-iron:9.8
G3-scope:7.3
G3-iron:4.7
HK21E:5.3
HK53A3:5.8
SKS:3.7
AK47:5.1
AK101:5.7
Bizon:5.8
PPsH41:2.6
PKM:6.5
MP5A3:5

'no model' means that either there is no model for that weapons or I couldn't find it.