Not even that. The Feds can fire torps at high warp. Just do torp drive bys all day every day.
And yes, anyone using a ballistic weapon would quickly kick the Borgs collective ass, but the Reapers seem to like giant lasers so I have to give it to the Borg.
I doubt the Borg could adapt to the Reapers weapon. Despite appearing to be a 'laser' it is in fact a highly efficient Mass Accelerator. It accelerates an incredibly hot beam of superheated metal at the target. And what it cannot destroy, it can literally bury beneath tons of molten superheated metal which will, invariably, cool.
So unless the Borg are able to adapt to that, then, well... They're boned. Also! If they can be Indoctrinated, that would be a severe kick in the crotch. Or even turned into Husks. I mean, they're already pretty close. But hey! Could be possible.