To get flint in New World, you will need to locate it on the ground in most major areas in the game. Often flint will spawn as small rocks and can give one flint per rock picked up by the player.
However, getting flint by finding it on the ground will take a while, and if you want to make bullets, you're going to need a lot of it. So what you can do to speed up your flint gathering is to farm flint at rivers and along the shore.
Related: New World Engineering Leveling Guide
Flint will show up easier along the shore, and you can also find large brown rocks that can give it along with stone, as shown below.
Mining these rocks counts as boulders, but they are different than normal boulders. You can tell these boulders from other ones by their color. If they have a muddy brown texture, chances are they are rocks that give flint, and farming them is the best way to get flint for crafting recipes.
Doing so will also level up your mining skill which is required to get other ores and materials required for bullets and gun powder in the game.
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