History of Frictionless Rail

Overview

Reducing friction on the rail allows faster loading and higher velocity, so it increases reload speed and projectile speed. The wiki dates it to Season 27 and does not list weapon types.

Destructoid calls it a free bump to reload speed and projectile velocity, similar to a mini Impulse Amplifier. On Submersion it is one of the rail options, alongside Low-Profile Rail, which trades some of this for more handling and persistence. No numeric values are given in the sources checked.