I write my loads and results in a 3 ring binder, and of course it's in chronological order. In more recent years I've been cutting out the groups on the target and scotch taping them into the binder along with the load notes.
Needless to say, I have some groups that take up an entire sheet of notebook paper...............
Pretty much my method as well.
I made a "Load Development" sheet in Excel where I can document the rifle, the bullet, brass (often noting # of firings), primer, date and temp. Below that I have multiple rows to document varying powder charges or changes in bullet jump. Columns in this lower section outline velocity, target distance, extreme spread and group size. I also keep the 8.5x11 targets 3 hole punched and include with this load development sheet for record keeping.
These are bundled in a large 3-ring binder that has tabs by rifle to keep it somewhat sorted. If I sell a rifle, I remove that section and stick it in another binder that stays on the shelf. I have twice had a rifle come back to me after selling. The first time I trashed my load data notes but wisened up. I was able to go straight back to my proven loads for the second returning rifle without missing a beat.
Edit: I recognize this is a stupid level of micro-minutiae for general hunting rifles but it lets my inner OCD geek do its thing while I enjoy my hobby.
