I just bought a sight extension for my kk300 and it has a dovetail along the entire length of it. At first I thought it would be a good idea to keep the sight all the way fwd for prone and kneeling and then back into stock position for standing, since my wobble gets really bad with it at the tip. This would double as an aperture change to a larger one..
Is moving the front sight globe fwd and back during a match a bad thing?
When you move the sight back and forth, you are changing your zero, as well as the tune of the barrel. These factors don't necessarily mean that you shouldn't do it, but they should be considered.
Im able to get the change in zero constant enough to within a few clicks when I change the sight position, but as far as what the different barrel tune that this introduces isn't something I can readily see, especially with my offhand abilities.