I believe you can never go wrong with 1 minute. That's from a warmed up barrel, for hot group shooting.
It shouldn't hurt barrel life nor the grouping.
Then there would be some interval between groups that works, and that doesn't work well.
You would just have to observe that.
For cold bore accuracy testing, I can wait 3hrs between shots.
But I found through adjusting this that a 10min shot rate is by far the worst performing. This has held for 223 through 260AI, light to heavy palma contours, factory hunting guns to 17lb BR.
So that's exactly what I test at(for cold bore). If it shoots good there it will shoot better with any other timing.
I just mention it because it's a timing to avoid for hot grouping.
If you wear glasses you might also consider a nemesis range. For me it's 200yds..
If I shoot good there, I'll shoot better at ANY other range.
So I do a lot of testing at 200yds, and 10min shot rate.