Fortnite's 4.5 update is out now, adding new weapons to both the Battle Royale and Save The World modes. Overall, it's fans of the Save The World mode who stand to gain the most here: that mode is getting a stink bomb, a new Freedom Herald Pistol, and new Stars and Stripes Heroes (pictured above) to celebrate Independence Day in the United States.
The Stink Bomb "unleashes a cloud that damages enemies over time", while the new Herald Pistol – which is available on the Weekly Store – "launches firecrackers that bounce off walls, and will knockback and damage enemies in a small radius when they explode". Also available in the Weekly Store is the Lynx Assault Rifle, a "slow firing burst assault rifle with above average headshot damage and excellent stability".
Those are all exclusively rolling out for Save The World. Battle Royale is comparatively slim, with a sole Drum Gun being added. According to the update, it's "a hybrid weapon that combines the stopping power of a rifle with the suppressive ability and fire rate of an SMG". It has 26/27 base damage (Uncommon and Rare) and uses Medium Ammo. You'll find it in chests, Vending Machines or on the floor.
The full update notes are over here.