The .41 Colt is closer to the .38 Special than to the .41 Magnum. I had a chart at one time that told how to make old cartridges from new. Will try to locate it. Maybe the .38 S&W case could be used to make the .41 Short Colt.Could probably trim down 41 mag cases. I'm just guessing on that though I'm sure there are some experts here that have some good answers.