Student or Learner
a line from movie《The Shawshank Redemption》
"and those bars slam home"
how to understand "slam home"?
It's in reference to the L-shaped bolt that locks the bar doors; i.e., it slams homes: it bolts, it locks.
Here's an example of the same meaning of 'slam home':
She had only a second to wonder before a door hinge creaked and she was pushed violently from behind. She fell, and heard the hasp slam home, a padlock slide through the eyehole, then click shut.