Photographer Marc Steinmetz features some really cool examples of home-made devices fashioned by prisoners in order to  escape. A few of them succeeded.

This shotgun was "made from iron bedposts; charge made of pieces of lead from  curtain tape and match-heads, to be ignited by AA batteries and  a broken light bulb.  On May 21, 1984 two inmates of a prison in Celle, Germany, took a jailer as a hostage, showed off their fire power by letting go at a pane of bullet-proof glass [bottom of picture], and escaped by car."

DOUBLE-BARRELED PISTOL
This gun was found along with other homemade firearms in the cell of two Celle prison inmates on November 15, 1984. The weapons had been made in the prison’s metal workshop. They were loaded with pieces of steel and match-heads.