WRT to shooting on public lands what is the consensus here on what is an acceptable amount of spent casings left behind? I like the idea of placing a tarp down to collect brass but I practice scenario or IDPA style drills when shooting and move around too much, spent brass can be anywhere. Regardless, typically when I’m done you cant tell I’ve been there (or contributed to anything already there from others) and its difficult to find any spent casings that are mine. I always pick up and walk around and try to find any and all spent casings but cant guarantee I get every single one, my rough guess is I get about 90%... give or take. If this is a problem, I’d like to recognize that and find a way to correct it. What say folks?