How to Change Project for Many Issues without Bulk Update Operation

I need to bulk update about 47k issues and move them to a different JIRA project. Not only does the bulk update feature limit this functionality to 1k issues at a time, but it times out even when I try to do as little as 500 records at once. I am looking for any other ways I can update solely the project for multiple issues using another method. I did a few tests using the CSV import but it didn't appear to work (only created a new issue in the other project rather than moving the issue from the old to the new project). If there are any free plugins or other ways to do this I am out of ideas!