Worth ticketing unless someone else can confirm this. I was fairly sure that rails have the same max range as beams (3km). Whether they attenuate over range is another question (I think they do which would be strange).
Definitely have to keep them on a separate fire button though, especially if you are using beams (burst and pulse you could conceivable tap the fire button without triggering the rails). Generally, I never bind different weapons to the same fire button.
I'd have two fire groups; beams primary, rails secondary in one. Beams primary, dumbfires secondary in the other. Rotate to either when needed. You'll always have your beams (free ammo) and just switch to whichever secondary you want when you need them.
Like schurem said though, don't waste them on shields. I think rails are listed as "thermal/kinetic" so technically they should do damage on shields as well but they work best on hull and especially for sub-system sniping (A penetration). You have to be accurate and steady though
