In general players use their knowledge of levels in order to spawncamp places where dangerous monsters will spawn, in fact the charge attack from a strike needle has enough power to take out nearly any monster that doesn't resist it.
You can use the regular attack but it is more of a ranged damage support, if you are going to use it in regular combat don't use the full clip (2 volleys is a full clip). Just fire one, move, and then fire again once you are in a good position.