Years ago I was shooting a 1911. Some one at the club got the brillant idea to use conveyor belting as a backstop at the pistol range. Well, the pistol rests were chained to the bench. I was shooting lead semi-wadcutters at 25yrds. Every once and a while after I would shoot a round, the chain, which was dangling under the bench would jump and rattle around. I was the only one on the range at the time. I finally figured out when I saw a semi-wadcutter laying under the bench that the bullets were bouncing off the backstop and hitting the chain. Weird. I was using a low velocity target load and the bullets didn't have enough power to penetrate the conveyor belt. Needless to say the backstops got changed.
Which also brings up the time I was deer hunting. I was shooting a Win. Mod. 70 in .338 WM. I had loaded it down to .33 Win velocities. I hit the deer in the lungs and dropped it. It wasn't until we got the deer back to camp and examined it that I found 2 bullet holes on the same side about 8" apart. The bullet had gone in and scrambled the lungs, hit a rib on the far side, turned around, and went through the liver on the way out the same side it went in. I almost shot a deer and myself at the same time that day. Bullets can do some really strange things at times.