Just go sam fisher style (conviction-era, mostly) and pop heads when you need to. Then its the perfect weapon for any warehouse/office/enemy base with tons of guards. The 10 mm pistol seemed really lame.until you upgrade it fully. I completely ignored the combat rifle and machine pistol, i've used enough of those in other fpses. I got the revolver at the start of the game and loved it, such a badass weapon, especially when you upgrade the rounds to EXPLODING BULLETS! I had that holstered whenever i was walking around the cities in case some thugs tried to threaten me.