haha that, I would have no idea about. Hearing the steel ring at 500...I guess that would depend on a lot of factors. The nrph and I shot a steel gong at 200 the other day while at the range. we could hear that, even with a 223 but it had his silencer on it.
I like watching this channel on Youtube. In this vid they're shooting the BMG at 3825 yards. There's 1760 yards in a mile.so...just over two miles.