In a dramatic shift for the US military, the army is considering the use of bullets that can expand and break up when striking a target to make new pistols more lethal, raising concern that doing so would violate international law.

According to the Army Times, the Pentagon recently reviewed the use of “special purpose ammunition” and determined the army could look into enabling its next-generation XM-17 pistol to use various kinds, including hollow point bullets. Currently, only ball ammunition is used in the army.