The P30 is a semi-automatic pistol which you spawn with. It uses 9mm ammuntion and can be found in chests.
This is a bad weapon, and should be immediatly discarded when you find any other secondary. It takes almost an entire clip to kill a single person (7-8 shots) and its spread is atrocious. It's only to be used in situations where you are attacked first, or in situations where you are fighting another new-spawn.