Are lasguns useful on the tabletop?

Just want to preface this by saying I've never played a legit game before, and some actual players are welcome to enlighten me, but can lasguns even kill anything? Only one attack that hits on fours on top of no AP, 3 strength and 1 damage makes it sound like it'd be hard to kill anything that's not chaff, and even then that might be a struggle. I know guardsmen aren't supposed to be crazy damage powerhouses, but have any players here actually managed to pull something off with just lasgun fire?