ChairGun Drag Models

[jonxmack]

Hey folks

I've recently got back into FT shooting after a long break and was looking for a way to generate my FT range cards. I know a lot of people run ChairGun but since it has been EOL'd and needs some minor hackery to get it to work on my M1 Mac for the last few days I've been working on a little web app.

I am a web developer by profession so I'm most comfortable using JavaScript and I was able to find a decent ballistic calculator I could use as a starting point, Yet Another External Ballistic Kalculator which I cant link to due to being a new member (although it can be found via google). However while it has the "normal" drag profiles it doesn't have GA which ChairGun uses.

A bunch of google searching eventually led me to this forum and one specific post about the GA profile by JungleShooter which was hugely useful, and then a whole bunch of posts from rsterne with lots of charts and data, so thank you very much, but I wanted to see if I could get the GA data for myself.

I did try to decompile the ChairGun.jar file to see if I could find the drag profiles in there but it just references .txt files and no amount of searching could find them on my machine. So instead I decompiled their android app to get the profiles out of that. I'm not sure they're the exact same as those used on the desktop app although I don't see why they wouldn't be, but I thought they might be of use to a few people here.

As a quick note: I have absolutely no ballistic knowledge whatsoever so if these are "wrong" then I'm sorry. Furthermore if posting this is against the rules then feel free to delete this post but I figured since the software is EOL anyway it's not really hurting anyone.

In the profiles the first digit(s) are the mach value, followed by the drag coefficient after the comma.

Here is the GA profile:

.0, 0.2442
.1, 0.2301
.2, 0.216
.3, 0.2036
.4, 0.1928
.5, 0.188
.6, 0.1937
.7, 0.2123
.8, 0.2601
.9, 0.3467
1.0, 0.4901
1.1, 0.593
1.2, 0.6411
1.3, 0.6591
1.4, 0.662
1.5, 0.6572
1.6, 0.6472
1.7, 0.6349
1.8, 0.621
1.9, 0.6071
2.0, 0.5932
2.1, 0.5802
2.2, 0.5688
2.3, 0.5579
2.4, 0.5481
2.5, 0.5398
2.6, 0.5328
2.7, 0.5262
2.8, 0.5211
2.9, 0.5169
3.0, 0.5132
3.1, 0.5108
3.2, 0.5082
3.3, 0.5069
3.4, 0.5052
3.5, 0.504
3.6, 0.503
3.7, 0.5021
3.8, 0.5018
3.9, 0.501
4.0, 0.5008
4.1, 0.5128

and G1:

.0, 0.2629
.1, 0.2487
.2, 0.2344
.3, 0.2214
.4, 0.2104
.5, 0.2032
.6, 0.2034
.7, 0.2165
.8, 0.2546
.9, 0.3415
1.0, 0.4805
1.1, 0.5883
1.2, 0.6393
1.3, 0.6589
1.4, 0.6625
1.5, 0.6573
1.6, 0.6474
1.7, 0.6347
1.8, 0.621
1.9, 0.6072
2.0, 0.5934
2.1, 0.5804
2.2, 0.5685
2.3, 0.5577
2.4, 0.5481
2.5, 0.5397
2.6, 0.5325
2.7, 0.5264
2.8, 0.5211
2.9, 0.5168
3.0, 0.5133
3.1, 0.5105
3.2, 0.5084
3.3, 0.5067
3.4, 0.5054
3.5, 0.504
3.6, 0.503
3.7, 0.5022
3.8, 0.5016
3.9, 0.501
4.0, 0.5005
4.1, 0.4788

I do have the rest if people are interested, and I'm sorry if this is in the wrong place!