there is some good shooting abilities like using Spiteful prodder, Loonking, Loonboss with Cave squig, and shooting spell at enemies. and of course I think the Squig Gobbla is still a decent artillery piece.
But yeah I don't think Gloomspite Gitz is meant to be play as a strong shooting army, they definitely shine in a melee, magic, and MW department. but they give you good options to do stuff at longer range