I forgot how fun old hard drives were.
I had a stack of them one time and proceeded to do some "scientific testing."
They're fairly bullet resistant up through pistol calibers. Then the SKS and 1903A3 came out.
Most fascinating was one particularly tough hard drive that was from the 1980s. What is lacked in storage density, it more than made up for with material density. I had a .30-06 tracer stick in it and not penetrate. It was fairly old ammo that had a noticeably delayed ignition for the tracing compound. After about 7 or 8 seconds, it started smoking like the dickens before burning an off purple, the petering out to some funky yellow smoke.