According to Forsyth, the folding sights on the English double guns of the mid 1800's, had all folding. Elevation for the point blank shooting, ie: from breech
to the front bead, was given by the larger breech of the gun. I find with mine, the boss of the base gives the necessary elevation for point blank shooting
and is equal to the first leaf, if raised. Thus, with the hunting load, I can shoot to about 110yards without raising a leaf. The other 2 leafs are set for 150
and 200yards.