That, and remember when these scopes were designed. A century ago internal scope adjustment was crude and very limited in travel. Also, it's easier to make a simple telescope without internal adjustment, allowing the maker to concentrate on the important stuff like optics. Another feature that some people don't get is that the adjustment knobs are actually micrometers and as such are precisely repeatable: make note of the windage and elevation settings, swap the scope onto a different rifle and then eventually back to the first rifle, re-set the knobs according to your notes and presto you're right back on target.A fella can theoretically make do with but one scope for all his rifles that way. (But like everything else in a rifle loonie's life, more is better!)
"You can lead a man to logic, but you cannot make him think." Joe Harz "Always certain, often right." Keith McCafferty
