I am new to the this forum, and also am relatively new to shooting. I have been going to the rifle range I belong to for a few years and practicing sighting in cheap scopes on .22's and things like that. While I think that was very fun, I recently have had an urge to get a gun to like 150+ yds accurately. I bought a Savage 340C in .222 caliber with the Weaver K10 60B on it from an old friend of mine. I originally had intentions of changing the scope thinking this one was maybe too old or something, but from what I have been reading online, this scope really is'nt half bad. At any rate I have a few questions, 1. I understand this scope has an adjustable objective, and on this scope there is a line on the objective, and you can spin the rear piece around on threads and it reads, 100ft, 50yds, 100yds, 200yds, and jumps to 1000yds. My question is spinning this I am nearly sure nothing happens to the scope, is there a procedure for using this adjustment, how does it work? Maybe Im just an idiot but I cannot figure it out. Any help is greatly appreciated.