I have a book for each gun, in which I detail things like measurements, preferred loads, round counts, and such. I still refer to them when it is time to load for a rifle, as each rifle gets its own load.
I have those books for revolvers as well, though I'm not quite sure where most of them are. I eventually got tired of finicky guns and so spent some money ensuring that each gun of a particular caliber is as dimensionally identical to the others as I could make them. Now, with very few exceptions, I can pick up any example of a particular caliber and know that it will work with my "standard" load.