Full Attack
You can spend a full action to make two attacks, each with a –4 penalty to the attack rolls. These attacks can be made with the same weapon or different weapons, though certain weapons have a firing speed so slow that you can’t shoot them more than once in a round, even with a full attack. These weapons have the unwieldy special property (see page 182).
Certain weapons have special individualized full attacks. For instance, some weapons have a fully automatic attack mode. Sometimes special full attacks, such as the soldier’s onslaught class feature, require specialized training in order to gain their benefits.
Source
Core Rulebook pg. 248