I see no need for adjusting a scope for 400 yard shots. Also would like to know how to train deer to stand still for ranging then fiddling with scope elevation dials before making a shot. My deer are too wild for that and don't stand still that long when out in the open where long range shots are needed. With a flat shooting rifle zeroed at 300 yards you can easily estimate hold over for 400 yard shots and shoot immediately. On land you hunt all the time you should already be familiar with ranges to landmarks so you know when to hold over a bit before the deer even presents itself.
I have at least 2 scopes with the big turrets but have never used them except for initial zero. They are both on heavy barrel varmint rifles.