The vertical lines (probably 6 of them on your bullet) running from the 12:30 to 6:30 show that you bullet was fired through a rifle barrel - the rifling in the barrel of the gun "grabs" the bullet as it's traveling down the barrel and puts spin on the bullet, like a quarterback throwing a nice spiral pass on a football, for increased accuracy. As far as the bullet not hitting anything, which seems to be the case with your, does happen, although somewhat rare since they can travel so far.