Blast

This weapon fires in a cone that extends only to its first range increment. You can’t use it to attack creatures beyond that range. For each attack you make with a weapon with the blast special property, roll one attack against each target in the cone, starting with those closest to you. Each attack takes a –2 penalty in addition to other penalties, such as the penalty to all attacks during a full attack. Roll damage only once for all targets. If you roll one or more critical hits, roll the extra critical damage only once (or any other special effects on a critical hit that require you to roll) and apply it to each creature against which you score a critical hit. You can’t avoid shooting at allies in the cone, nor can you shoot any creature more than once. Attacks with blast weapons ignore concealment. A blast weapon doesn’t benefit from feats or abilities that increase the damage of a single attack (such as the operative’s trick attack). Ammunition for blast weapons is designed for blast attacks, so you spend the usage amount only once for each cone of attacks.

Source

Core Rulebook pg. 180

This website uses trademarks and/or copyrights owned by Paizo Inc., which are used under Paizo's Community Use Policy. We are expressly prohibited from charging you to use or access this content. This website is not published, endorsed, or specifically approved by Paizo Inc. For more information about Paizo's Community Use Policy, please visit paizo.com/communityuse. For more information about Paizo Inc. and Paizo products, please visit paizo.com.