On my dad’s list of Things You Must Never Do With A Gun, shooting at a rock was in the top 5.
Is he crazy or stupid?
We had a huge stack of railroad ties that we put targets on.
No stray bullets/shrapnel, ever.
“he is a self professed expert in guns and gun safety”
Important though unusual rule about guns:
If you are ever around a friend who is armed, in the field, it is essential to find out if they have ophiophobia (abnormal fear of snakes.)
It is almost a unique rule, but one that is serious as a heart attack, because it presents a life-threatening danger to them and everyone else around them.
Because when somebody has ophiophobia, if they are armed and in the presence of a snake, they utterly lose their common sense.
I have seen highly intelligent, disciplined, well trained soldiers totally lose it in the presence of a snake. And they will use any weapon near their grasp in the worst possible way.
One example was a senior NCO, standing in a rocky dry river bed, pointing a .45 at a snake almost between his feet, while a dozen other screaming and running people were yelling at him to hold his fire. “It’s okay,” he said, “the snake is on sand!” Yeah, about a half an inch of sand over a round river rock.
Another one ruined his expensive chrome cavalry sabre by chopping a *rubber* snake into small pieces on a concrete floor, with a two handed, terrified and screaming swing.