I've struggled with load development as much as anybody so I can't give good advice, but one thing that occurs to me is: in the last 20 years or so, there are so many factory loads that shoot lights out in modern guns, using factory deep seated OAL dimensions....it makes me wonder if chasing the lands isn't secondary to barrel harmonics?

Well this is a fine pickle we're in, should'a listened to Joe McCarthy and George Orwell I guess.