Necro Helmet

This is the ranged answer for the back half of pre-Hardmode, and it opens up once Skeletron is dead and the dungeon is safe to walk into. A melee character has Molten armor waiting in the Underworld with far more padding. What you get here instead is a real lift to bow and gun output, plus better odds on a critical hit with all three pieces on. The full set also trails an afterimage behind you and swaps your hurt sound for a skeleton's rattle, which is flavor rather than function, though it does make damage harder to notice by ear.

Both materials come from the same trip. Bones drop off almost everything down in the dungeon, and Cobwebs fill any large cave nobody has touched yet, so the routine is to clear dungeon rooms until the bone count is there and strip webs on the way in and out. Webs slowly grow back where they were cut, so a cavern you have already emptied is a supply you can return to if you come up short. On a drunk world the boss is optional for this, since dungeon enemies spawn there before Skeletron has been beaten.

There is a second headpiece. Angry Bones, Dark Casters and the book-throwing skeletons occasionally cough up an Ancient Necro Helmet, which wears the game's original artwork but behaves exactly like the crafted one. Either piece completes the set, so a lucky drop is a helmet you never have to make. If you want the other look later, shimmer converts one into the other and back again.

It carries a ranged build through everything left before the Wall of Flesh, and the first Hardmode ore set you can smelt replaces it outright. Do not expect it to hold up in melee range. The defense is thin for that point in the game, and the whole set assumes you are shooting from somewhere the enemy is not.