If you have a piston that uses a 2nd ring from Venom it would normally be .001" bigger gap then the top ring. I set my top comp ring at .013" and the 2nd (if there is one) at .014" and the top oil at .015"-.016", the oil scraper butted together NOT cut or shaved any, and the lower oil scraper at .018"-.030".
They actually make a tool for ring end gap filing. It keeps the end gap straight and square. I however use a dremel like Greg, and want to add that it does make it alot faster, but can also take to much off.