You gain the following benefits.

Ability Score Increase: Increase your Dexterity score by 1, to a maximum of 20.

Ignore Loading: You ignore the Loading property of the Pistol and Musket (all called firearms elsewhere in this feat). If you’re holding one of them, you can load a piece of ammunition into it even if you lack a free hand.

Headshot: When you score a Critical Hit with a firearm, you can roll one additional damage die when determining the extra damage the target takes.

Ricochet: When you miss with an attack with a firearm on your turn, you can use a bonus action to repeat the attack against a different creature. If the new attack hits, you don’t add your Dexterity modifier to the damage roll, unless that modifier is negative.