Interesting responses. The Army is different these days for sure. I took this photo two years ago doing M777 and M119 training. You don’t have to wear headgear at all unless on the gun. And you can see by the helmet on the ground that that is not a no-no either. There were helmets and assault packs lying around all over, along with a host of other items. No, it seems that the real issue lies with the soft cap itself. It goes back as far as a shoot I did at Fort Carson in 2010. So it’s been going on since at least then. I wondered if anyone knew of it prior to that.
So the answer to my question is - the reason you don’t leave your soft cap on the ground is because this will happen to it.
It gets fired through the tube!
I suppose it’s like SF where if you leave your computer unattended all sorts of things can happen: It gets left on a porn site, weird messages get sent to people with your stamp, or someone simply puts a screen shot of your screen on the screen, so that your mouse doesn’t work and you can’t figure out what’s going on with your computer.