This planet ain't big enough for the two of us, Helldiver...
The R-6 Deadeye unlocks at level 35 and appears as the Marlin 1985 SBL (Bernetti Rangehitter).
The Deadeye is a true-to-Helldivers 2 lever-action rifle with a rounded (shotgun) reload, high damage, accuracy but significantly low stability. It cannot be modified, and comes with a 1.5x optic by default. Perfect for mid- to far-range combat. The stats were taken from Helldivers 2 and "PAYDAY-ified".