I have a old Bostitch stapler and I am not sure what size staples it uses or if they even make staples for it anymore. I saw a video where a guy put 3/8" staples in one that looked just like mine, but they didn't fit. I also tried 1/2" 12mm and 9/16" 14mm. It needs staples bigger than 9/16". The hardware store does not carry anything bigger than 9/16 so I would rather not have to order online and still not have the right size. Thanks