There is a Legacy version
here.

Dueling PistolItem 1
Uncommon Concealable Concussive Fatal d10 Source NPC Core pg. 50Favored Weapon Kaldemash,
UssharassimPrice 12 gp;
Damage 1d6 P;
Bulk L
Hands 1;
Range 60 ft.;
Reload 1
Type Ranged;
Category Martial;
Group FirearmAmmunition Firearm Ammunition (10 rounds)
Made for settling disputes when diplomacy fails, dueling pistols are finely crafted and made to fit easily into a holster or pocket.
Traits
Uncommon: Something of uncommon rarity requires special training or comes from a particular culture or part of the world. Some character choices give access to uncommon options, and the GM can choose to allow access for anyone. Less is known about uncommon creatures than common creatures. They typically can't be summoned. The DC of Recall Knowledge checks related to these creature is increased by 2.
Concealable: This weapon is designed to be inconspicuous or easily concealed. You gain a +2 circumstance bonus to Stealth checks and DCs to hide or conceal a weapon with this trait.
Concussive: These weapons smash as much as puncture. When determining a creature's resistance or immunity to damage from this weapon, use the weaker of the target's resistance or immunity to piercing or to bludgeoning. For instance, if the creature were immune to piercing and had no resistance or immunity to bludgeoning damage, it would take full damage from a concussive weapon. Resistance or immunity to all physical damage, or all damage, applies as normal.
Fatal d10: The fatal trait includes a die size. On a critical hit, the weapon’s damage die increases to that die size instead of the normal die size, and the weapon adds one additional damage die of the listed size.
Critical Specialization Effects
Source Core Rulebook pg. 283 4.0Certain feats, class features, weapon runes, and other effects can grant you additional benefits when you make a Strike with certain weapons and get a critical success. This is called a critical specialization effect. The exact effect depends on which weapon group your weapon belongs to, as listed below. You can always decide not to add the critical specialization effect of your weapon.
Firearm: The target must succeed at a Fortitude save against your class DC or be
stunned 1.
Specific Magic Weapons
Coldstar Pistols,
Redeemer's Pistol,
Tiger's Claw