T here are a few systems using 40 mm grenade launchers or 30 mm automatic cannons with proximity rounds to destroy drones. Examples are the Striker SHORAD with Stingers and a long barreled 30 mm chain gun, possibly a laser weapon, and the Raytheon Pike which is a 40 mm grenade launcher fired missile. These systems are going to get a lot of interest for anti drone defense now.
You seem to be very knowledgeable. In general warfare between the US and China (prior to crossing the nuclear threshold) how safe are American carriers sitting off the coast of Taiwan?