Depth of seating changes with use and i have personally never found any bullet perform really noticeably better or worse ( unless you go way too short or are getting well into contact ) in a hunting rifle . Precision BR ? yeah tweaking the length with coke can manufactured washers in the dieMay I ask what seating depths you've tried? Think I'm at a 80thou jump with good results
The Rifling is always changing in use and if your not into using high end bench rest bullets ... You will find small batch differences ! Small changes yes but not anything truly useable in general terms in the field . In a paper punching BR comp sure but then the rifling is always eroding away , so its not static .
The TTSX are imo just too long to work to the highest degree in a 1-12
