I love it when a watch winds silky smooth. What would one suspect when an otherwise near-pristine piece winds in a grinding sort of way?

The castle or crown wheel is worn and is slipping when you are winding winding maybe.

Francesco

Gunk in the winding gears, a bad winding gear, a winding gear put in upside down (dont ask how I know), rust in the pendant, and wear in the stem/sleve are a few of the possibilities..

Thanks, guys. It's going into the shop today. I'm not touching it (still into the low jewel stuff, thanks very much).