Pretty cool, I guess that's what happens when you fire a high calibre gun with a muzzle brake on a dusty ground,
lol.
There's a few videos of Pak-40's firing. This one is cool, especially at the end with the slow mo where you can see the live round kicking up dust...
https://www.youtube.com/watch?v=4X-yIkXX3fA
Or watch the dude firing this one, seems he wasn't quite expecting such a shock wave,
lol....
https://www.youtube.com/watch?v=PR9vqJZkmJY
Or the 88 on a Jagdpanther...
https://www.youtube.com/watch?v=L0KDnIsZe5Q
I'd like to hear the 88 in person as I'm guessing the video doesn't do it justice.
Or some old school videos of Tigers firing their 88's.
https://www.youtube.com/watch?v=SYMYdVt_CTE