You are exactly right. I am almost certain that he problem with my old Burris and leupy scopes is they used a non-synthetic, stiff grease in the adjustment mechanisms, because they will move one way just fine but not move back the other way. This tells me they're moving under screw pressure since they are forced to but when asked to move back with the spring, the grease has become too old and stiff to let it move freely.Seems like the problem today is tracking--- I'm wondering if it's always been a problem but with today's long range shooting-- and internet info-- I'm thinking more people are actually either dialing or checking tracking--- I'm guessing 40-50 years ago lots were just doing a "set ot and forget it" and hunting at 300y and closer and using "Kentucky windage" for adjustment
As you put it- because of long range shooting, modern scopes have to track perfectly up and down and because warranty 'not tracking" problems have shown their head so prevalently now, quality scope manufactures had to find a lubricant that stays viscous at low temp and over long periods. That, and stronger springs.
I figure burris went with the posilock thing way back in the day because of this very reason.