Steinhardt's Guide to the Eldritch Hunt, pg. 173
You know your firearms inside and out and are a master at handling them. You gain the following benefits:
• Increase your Dexterity score by 1, to a maximum of 20.
• Weapons with the Barrel (S) property count as weapons with the Barrel (F) property for you.
• You can ignore the Barrel property of weapons with the Barrel (F) property.
• Being within 5 feet of a hostile creature doesn’t impose disadvantage on your ranged attack rolls.
• You do not have disadvantage on ranged attacks against prone creatures within 30 feet of you.