Destiny 2 Luna's Howl god roll guide: Best perks, barrels, and magazines
Since you'll have some handling or stability through your 3rd column perk, Hammer-Forged Rifling or Smallbore are a good barrel choice to buff your effective range. Magazine wise, High-Caliber Rounds provide extra range and flinch, while Ricochet Rounds offer range and stability plus can be fired around corners.