There is no standard depth for seating any caliber bullet in a case neck. Whatever grips the bullet to hold it in place when another round's fired and lets it feed from the magazine reliably is good enough. One caliber deep past the case mouth's a myth that started decades ago.
The bullet's jump to the rifling is not critical until you shoot your stuff into no worse than 1/4th MOA at 100 yards. And with a given OAL set up with a new barrel or bullet, remember the rifling throat grows longer about .001" for every 10 to 30 shots fired; depends on the amount of powder burned and powder types. Are you going to seat them .001" shallower every dozen or two shots?
With over the counter sporting rifles and military rifles, one typically will not notice any difference in accuracy while the throat erodes away 1/10th inch from its starting point. So, I don't think it's worth the time and ammo to shoot a few groups to see which one's the smallest for a given OAL. Especially when no two groups of the same load are the same size anyway; the smallest one you shoot happens just as often as the largest one.
Seat bullets 1/16th inch shorter than magazine length the shoot them. If accuracy's not good, change the charge weight by a full grain, then try again.