When I’m working with a new rifle, I make notes in my range book on where the first shot goes if I’ve cleaned it or even if it’s been a while since I shot it last. I note barrel condition, cold, clean or cold, fouled.
I’m currently working up loads in a used 300 Wby which I had treated with DBC when I got it and after a round of 20 shots, I cleaned it and a week later was testing some more loads with a different powder. I got lucky and the first shot of the day was in the group of 0.85”. I’ll check it again later to see if it’s a trend. Of course that’s not how it always works but I’ll find out over time. Then I’ll do what it takes to ensure a good first shot.
