Not to be confused with the SPAS-15.
The Franchi SPAS-16 is a prototype automatic shotgun.
The SPAS-16 was probably entered for the Close Assault Weapon System program. However, it was never adopted as the project fell through.
The SPAS-16 is a fully-automatic version of the SPAS-15, which it is based on. However, only one picture of the weapon exists, so it may be slightly different internally.