The Borg were not seen as especially vulnerable to hand-to-hand tactics or projectile weapons.
Picard got away with it because he used it for the first time ever on 2 lone drones.
We don't know if the Tommy gun would have the same effect on the third or fourth drone (same goes for Worf's knife).
Furthermore, if Federation make-shift personal shield can deflect projectile weapons and stop people from going through them, then it's likely Borg personal shields can as well.
If you recall, the Borg hadn't adapted their shields for hand-to hand combat because in numerous situations, our heroes were overpowered by sheer numbers or were limited with time (examples include First Contact, and Voyager: Unimatrix Zero).
Furthermore, for those who say that there must be a limit to their adaptation:
Borg tech is much more advanced compared to the Federation, let alone early 21st century Earth.
It's very likely the Borg were able to find ways to absorb ridiculous amounts of power/blows/whatever, before their defenses would fail.
Picard got away with it because he used it for the first time ever on 2 lone drones.
We don't know if the Tommy gun would have the same effect on the third or fourth drone (same goes for Worf's knife).
Furthermore, if Federation make-shift personal shield can deflect projectile weapons and stop people from going through them, then it's likely Borg personal shields can as well.
If you recall, the Borg hadn't adapted their shields for hand-to hand combat because in numerous situations, our heroes were overpowered by sheer numbers or were limited with time (examples include First Contact, and Voyager: Unimatrix Zero).
Furthermore, for those who say that there must be a limit to their adaptation:
Borg tech is much more advanced compared to the Federation, let alone early 21st century Earth.
It's very likely the Borg were able to find ways to absorb ridiculous amounts of power/blows/whatever, before their defenses would fail.