CaptainB is correct on the airsoft barrel recoil issues. Some tanks will make the possibility of the airsoft recoil very hard to manufacture or wouldnt work as well, hence the Tiger 1 being the starting point to work on and test. The Tiger 1 we actually separated the barrel so we could get the recoil effect we wanted, but we also had to change the mantlet a bit to match this as well. So far the airsoft barrel recoil system has been very popular but we are still unsure of the release schedule for other tanks as this time. I personally love it though and with some thought it is pretty easy to make this an IR tank as the same time
As for the video they are referring to, you can find it below:
https://www.youtube.com/watch?v=PUslO6hEG5o I take apart and reassemble the airsoft recoil system in the video so you can see how it works. If the video doesnt do it for you then you can always buy the turret and break it down and study it, the plastic one is around $80ish atm on our site RTR but of course it is for the Tiger 1 so you would have to use it for study. Hopefully this helps!