One detail I had forgotten was from "Spirit Folk"[VOY6] in which the Fair Haven Irish holodeck townsfolk shoot the control panel with a double-barrel shotgun. Reviewing the episode, sparks fly and the internals flip out but there is no appreciable external damage.
The range is short and assuming birdshot, this is quite surprising. One would expect the black panel interface to go completely and not just flicker.
However, I think it more likely that the panel was damaged by the impact of forcefields and photons rather than by physical impact. This seems supported by the blue smudgy effect on the panel, similar to the effect seen on frozen characters a moment later, not to mention the lack of recoil.
"uring "Spirit Folk" (Season 6, Episode 17), the Irish villagers can be seen using Double Barreled Shotguns to capture Paris and Kim and to damage the Holodeck controls. Another shotgun can be seen in "Author, Author" (Season 7, Episode 20) in Captain Jenkin´s (Kate Mulgrew) quarters."