DANGERS EXIST!
At a range session years ago, a buddy decided to shoot at a car abandoned by the local Police (they used as a barricade, and locals shoot holes it).
Well, I'll shorten this up.... A good shooter (pistol, though) decided to go for the exposed rear brake drum from about 70 yards. Three shots in, while I watched, he shot a round in. It made a U-turn. and at a slow-enough-to-be-visible speed, came all thee way back to us. I ducked right, but it hit me in the left collar bone, near the shoulder. Drew blood, even after catching the edge of a bullet "resistant" vest under the uniform. [All ok, though].
Inspection of the brake drum found that half the bullet hit a round-bottom drill-hole (made to balance the drum). Hence, the perfect U-turn.
Just thought I'd better share that before you try it....