Early Game Tip: Are Shotguns Useless?

Early in the game, after clearing a few stages, you'll get blue items, unlocking the machine gun and shotgun. I've heard shotguns are usually the best for close range, so I tried it out. But when zombies come in waves, the shotgun has a small magazine and isn't automatic, making gameplay difficult. Unless it has a piercing 특성 (trait/specialty), I think it's a weapon to discard. Also, there's a spinning saw blade in the "In-Play Tech" (or similar upgrade path) that's pretty good.