Railers fire extremely quickly compared to ordinary sniper rifles. The projectiles they fire bounce off surfaces and pierce enemies. They consume 2 ammo per shot.
Railers have greater base damage than equivalent-level sniper rifles but have a multiplicative penalty to critical hit damage. Functionally, this reduces the effectiveness of critical hit bonuses; the larger the bonus, the less effective Railers will be when compared to regular sniper rifles, making it an especially poor choice for Zer0 but better for non-traditional sniper characters such as Axton.
Depending on which manufacturer the Railer spawns with, the weapon can have varying properties:
Maliwan - Higher elemental effect chance. Impacts cause a small splash effect.
Dahl - Burst fire while zoomed.
Notes
The Railer is obtained randomly from any suitable loot source.
Zer0's B0re skill does not affect this weapon because it already penetrates enemies, overriding the ability to trigger B0re.
Gaige's Close Enough skill can trigger after the weapon has pierced through an enemy. It cannot cause further damage to the initial target but functions normally when bouncing towards other enemies.
Trivia
The Railer is a direct reference to railguns, weapons that use immense electric currents and the magnetic fields they generate to accelerate conductive projectiles (or sabots containing non-conductive projectiles) to incredible speeds.