I'm telling that it's useless as a MM sniper only becaue of it's function, let's say snipe crits (and it would crit even without the buff) the buff gets eaten by the snipe which makes this cd used without the need for it.
I would change it like that: U use the cd the buff pops on ur buff bar and u fire snipe if it is a crit (because of ur crit chance, not because of the buff) the buff isn't used. That's my only problem for this cd, it gets eaten even if it doesn't have to be, which makes it a waste.