I also keep records: with over 15 guns I would manage to get mixed up and frustrated with out them. The most interesting things in them are the differences in wear and repair that affect the groups. An other interesting difference is the difference in loads bullets and sabots that shoot best after lapping or polishing a barrel. I also keep a note book with shot targets, some times I try to read the patterns the same way as I learned to do with cartridge guns, it helps tune and fine tune loads.