Bard and Wanderer's Minuet use it

[Sylve]

Interestingly enough, the cross-class skill Feint will still be fully Instant cast under the effects of Gauss Barrel. Assuming that Wanderer's Minuet more or less functions the same way, Bards under WM can still have good mobility when they need to move; opting to use Feint instead. Feint has a 120 potency attached to it, albeit slightly weaker than a Heavy Shot, but is still quite strong and nothing to scoff at considering the 30% damage boost. :O

Tis probably a bug. I wouldn't get used to it, GB and WM explicitly state "All weaponskills". Assume it'll be fixed.