Well, what it does to a tree, depending on the type of tree is splintering. Without a hole to focus the charge about the only thing it will do is bring stuff from above down I would expect. Anything loose between you and the can will project toward you, and the projectile will be hitting rock and that is never a good idea. You need 50 yards or so for somewhat safe distance, with rock you may want 100 yards. Let me know how that turns out.....[/QUOTE
Not sure what one you was using but the ones I've had experience with said 100 yds. safe distance on the container. Maybe yours was smaller. IDK Don't think I would have wanted to be any closer and the second one we was farther away. Believe me the rock showed evidence of an explosion.