According to the show, Gibbs went from his issue SIG .40 S&W to his Daddies 1911. But if his Daddy was a P-51 pilot his issue gun would have been a S&W Victory or Colt Commando, BUT it could have been a private purchase by an Officer and Gentleman.
Major changes for NCIS, Abby is leaving, Ducky is on leave, and the cute girl has been dropped. And McGee grew a beard. New characters to come.
Geoff
Who noted the hammer down in several episodes.