Offensive sets

The best way to start off would be to get anything with Weapon Damage as the core attribute. Regardless of the set, you'll deal more damage with your guns the more of this attribute you have.

To take your build further, a list of the Weapon Damage-focused Brand and Gear Sets and what they specialize in are listed below:

Brand Sets

Set name	Set bonuses
Airaldi Holdings	Marksman rifle damage, headshot damage, and damage to armor
Ceska Vyroba s.r.o.	Critical hit chance, hazard protection, and health
Douglas & Harding	Pistol damage, stability, and accuracy
Fenris Group AB	Assault rifle damage, reload speed, and stability
Grupo Sombra S.A.	Critical hit damage, explosive damage, and headshot damage
Overlord Armaments	Rifle damage, accuracy, and weapon handling
Petrov Defense Group	LMG damage, weapon handling, and ammo capacity
Providence Defense	Headshot damage, critical hit chance, and critical hit damage
Sokolov Concern	SMG damage, critical hit damage, and critical hit chance
Walker, Harris & Co.	Weapon damage, damage to armor, and damage to health

Gear Sets

Gear Set name	Summary
Aces & Eights	Specializes in amplifying marksman rifle damage.
Hunter's Fury	Specializes in close-ranged weapon damage and disorienting enemies.
Negotiator's Dilemma	Specializes in critical hit chance/damage and weapon damage against multiple targets at once.
Ongoing Directive	Specializes in Bleed damage/duration and weapon damage against Bleeding targets.
Striker's Battlegear	Specializes in accuracy and rate of fire, rewarding consistent and constant shots with weapon damage.
Tip of the Spear	Specializes in improving Signature Weapon damage and weapon damage in general.