The only reason to do it would be to catch models under an impact template. Even then, it would be a very rare situation where it would be worth it. Edit: are we assuming the mine was discovered first? I guess it depends on why the question was asked. Q: Can a mine be shot at if it has not been discovered first? A: Probably not No (see Ian's post below). It goes straight from camo token to off the board. Q: Can a previously discovered mine be shot at to prevent it from exploding on the model that shot it? A: No. Q: Can a previously discovered mine be shot at with an impact template weapon to catch other models and even other camo markers in the impact template? A: Yes. Note that if the answer to the first question is actually "yes", you simply need to remove the "previously discovered" qualifier from the next two.
Bear in mind that Mines don't declare Skills or AROs, so if it was a Camo Marker it goes straight from being a Camo Marker to being removed - there won't be a Mine to shoot at!
