Oil scraper ring- filing

Hey guys got a question about filing end gap on oil scraper rings. They are total seal- 3mm oil control , was checking end gap and I have a couple a little tight, total seal specs .015 min all were good except for 3. They were around .012. I have never had to file a oil scraper ring before. My goodson ring grinder is not working for them. Seems to aggressive. Ring just chatters. Would a jewelers file work. I have one some were, I think lol. Thanks cory

The rail "may" be too hard for a jeweler's file. You might try a sandpaper covered fingernail file. File in one direction ( toward the center of the ring). .0015 is too tight , .015 is just right. A 3mm does need to run a tighter gap than a 3/16ths.