A few weeks ago at a cutting demonstration with my portable sawmill
, I managed to slice a bullet cleanly in half. Some of the urban lumber I've cut had so many nails in it, they probably had more value in scrap metal than in lumber! Even woods trees have deer stands (and steps leading up to them) nailed into trees. Some of the other things I've cut into have been an ax head and a walnut tree that was hollow and had been filled with cement! Here is a photo of a walnut log that had fence wire in it. I used a bi-metal blade, which is designed for cutting wood with nails. The grain and color of the wood was beautiful!
I've heard of people finding wrenches, bicycle parts, and even a civil war era rifle barrel embedded in trees. I'm curious as to what others have found in logs, either with a chain saw or on the sawmill.