Opening Metal Bottle Caps on Shabbat

You may not open metal bottle caps on Shabbat if doing so will leave behind a metal ring. You may break the ring or open the bottle (and close it again, if desired) before Shabbat.
Note If you need the contents for Shabbat (such as if it is a bottle of wine), you may ask a non-Jew to open it for you.  But if the wine is not cooked/mevushal, the wine will become non-kosher once opened and handled by a non-Jew.