Nano Bullet

Every hit flips the target around, so anything that walks turns and wanders away instead of closing on you. Against a melee crowd that is close to a stun, and it costs you nothing per shot because the whole recipe comes off NPC shelves rather than out of a farm.

A shot that hits a wall ricochets toward the nearest enemy instead of dying, at reduced damage. That makes these the bullet for fighting around corners. The Hardmode Dungeon and a Solar Eclipse are the obvious cases, where you spend the whole time firing into rooms and stairwells you cannot see. Pair them with something that sprays, like a Tactical Shotgun, and a corridor clears itself.

Keep the Chlorophyte Bullets for bosses and run these for everything else. Almost nothing in the Dungeon resists confusion, with Dungeon Spirits, Giant Cursed Skulls and Paladins the exceptions, so the debuff is close to universal there. A Flask of Nanites does the same trick for a melee character. Bosses shrug it off entirely, so this is a clearing bullet, not a boss bullet.