Sight height(s) above the bore & sight radius needed, seems to me.
With it being 5" low, I would automatically file 1/8" off the top of the front sight.
Then, about .050" per filing job until zeroed where I wanted it, likely 1/2" high at that range.
I have only ever shot and filed while at the range. My .69's sights were 'made' .050" shorter to the middle
of the front sight. That gave me zeros at 25 and 50yards with plinking load, and 100 yard zero with the hunting load.