I'm not yet sure if it works on coin yet. I will tell you when I'm sure of it.
Ok in the video I only had 2000 gp because 2 days ago I got ak camo. I only show u about where to stop truning.
The thing is that you have to buy 10 crates press open later buy another 10. Then open them and at the 15th crate normally you should get the perm gun you want !
Tested on: Desert Eagle Camo, Ak47 camo and Xm8-adv