Some years ago in Denmark, at a European championships shooting sports event, I met a Japanese competitor who mentioned that they must return every single spent

Some years ago in Denmark, at a European championships shooting sports event, I met a Japanese competitor who mentioned that they must return every single spent casing from their previous purchase of ammunition before being cleared for a new purchase. He underlined that it's causing a lot of trouble in certain shooting disciplines, with marksmen ending up manically searching for their empty casings at the range, and that even the Japanese military is subjected to regulations forcing them to leave not a single spent casing around. Unlike how it's done in every country here in Europe, they apparently regulate/count ammunition sales down to each individual cartridge.