[Dante]

As the father of a 15 year old boy, my hypothesis is that it was left there by a young man who caught hell when he and/or his father finally realized the rifle had been left behind

[Brucester]

Such a find. Did you notice the stock? I found an spring board propped next to an old growth stump. I just left it, no need to be reminded of what it was originally used for. Cool finding old stuff while exploring, taking an image and leaving it for someone else to discover!