Red Dot Windage Adjustment

[TKE921]

I have a red dot scope on my shotgun and I was doing some adjustment a few days ago.  The Mfg says the adjustment should equal about 1/4" at 50 yards however when I move the dials each click seems to be more like 1" per click at 40.  Is this normal, something noticed because I am adjusting a shotgun and not a rifle, my not so great vision, or a problem with the red dot?

[catclr]

The ones I have click=1/4" @100 yds.  I make adjustments then use cheep target loads and shoot target and see if center was moved to where I want it. Adjust more if needed and end up shooting your hunting load as last shot to check it.