Yes, shots were fired. An example:

Officer Lowe fired his pistol to ward off passengers trying to climb over the Titanic's side, as his lifeboat was being lowered.

At least 2 other officers reportedly used their guns to "restore order". I'll have to dig through my Titanic books to 're-find' this, but I do remember reading about shots being fired. I have several books on Titanic, from Dr. Ballard's Discovery of the Titanic to The Complete Idiot's Guide To The Titanic (ha-ha!). The best book in my collection (by far) is Lawrence Beesly's Loss Of The SS Titanic! It has a June 1912 copyright in it! This tells all about the sinking, straight from the survivor's mouth! Like I said, it's by far the best book I got.