another point to remember is that side ao has one more glass element than front ao., which means the basic lens design combinations are different between the two scopes and could be the reason some people report a cleaner site picture. because of finer thread pitch front ao usually turn thru a greater distance and have more refinement in the final adjustment. Most side ao on better scopes, do not have backlash problems, tactical scopes in particular. Shooting large game animals, parallax is rarely a problem and most of the time the ao can be left on the more distance ranges, without a problem. The less the magnification range of the scope the less the problem, also as errors in parallax are magnified less.
