It happens. I hit one cutting firewood not long ago. It makes a mess of the cutters. That was a 98 DL chain that's now a 60 DL. If you don't have a rivet spinner, you lose a chain.
I hit a polyethylene rope that was embedded in a log while milling. Didn't hurt anything. But, that was bizarre. I started getting green sawdust Someone had tied a rope around the tree and it just grew over it. Wish I had taken a picture.
Bluerider was milling an elm tree and hit two 1/2" bolts and a ceramic insolator that someone put in/on the tree many years ago. He was the lucky guy to find all of them with his saws. I saw the piece yesterday. He dulled a .404 chain real bad, but it sawed through the bolts and then broke a 3/8" chain on another saw on th ceramic insulator.
BLUERIDER, I sawed up the remain wood after I cut away the section with the bolts/insulator, Bernie is going to use that piece for splitting on.
jerry-