When you start getting down to the fibers, that's when you start wearing on the actual construction of the arrow. Not good.

I've shot these into bag targets, 3D's, dirt banks, tin cans, plastic bottles tree trunks, old tires, cow pies... No problems or wear.

I did get one of them T-boned by another arrow at a 3D shoot. It nocked the covering off in one small spot about halfway up the shaft. I took the arrow home, checked it for cracks, spine discrepency and straightness. It was fine. I'm still shooting it.