RE: vapor trails
I've seen it and it wasn't even a humid day. It was late afternoon in mid june and we were shooting at dogs in the grasslands on a ranch. We started seeing it and wondered what in the heck it was. We were taking longer shots from an elevated position and it was near the end of our trip, we had gotten pretty good at holding on target with the minor recoil of the rounds we were shooting.
It was almost freaky. I think I noticed it first on a couple of my rounds and then was spotting for a buddy and saw it with his. I was starting to think that I had been in the sun for to long. It is really cool to see almost like something out of a movie.
This bubbly, expanding trail that ends with a dog popping!
I haven't seen it ever at the range our in any other type of hunting situation, but that may be due to the lack of rounds shot in one position for the majority of different types of hunting. I rarely spot for some one at the range and so don't get the chance to see it there.