https://www.pcgamer.com/fortnite-may-be-getting-a-sniper-rifle-that-can-shoot-through-walls/

A new sniper rifle capable of shooting through walls could be coming to Fortnite, according to a new item entry data mined by Fortnite hub Storm Shield One. 

The "heavy sniper rifle" is described as a slow, bolt-action weapon that can "pierce through the first wall it hits." Its item entry shows 157 damage and a reload time of four seconds, which is much higher than a standard legendary bolt-action sniper rifle's 116 damage and 2.7 second reload. Coupled with its piercing effect, this would make the heavy sniper rifle the most lethal long-range weapon in Fortnite, provided it is indeed real.