What to do when Ore runs out?

[Gisborne]

I just got the crossbow and its used up all my silver to craft bolts, which are obviously limited, now i have no silver and ive mines most silver miens in my world, even if i find more deeper int he game in the future, this means ammo just eats all our finite metal ore resources, pretty dumb

[HotRock]

Ello Kinsman, I would run out o ore in me adventures, but fear not, laddy for you can take yer dwarf and find a different location [World]. With more locations ye can take ye spoils and transportem to ya primary domicile [Your first world] and storem dere!

[RPG Gamer Man]

You can also find random rocks that litter around the places. If you use your pickaxe on these, they will give you a random ore or some coal. Look at the colors of the rocks and you can usually tell what they give you. It is in limited supplies, but it will suppliment any ores you run out of. These are usually the ones that fall on people, so keep your eyes open.

NOTE: These rocks will always fall down and them you can mine them. They seem to be endless.