Put on a taller front sight. Seems a lot of those old rifles shoot high! Could be the difference in todays ammo. I have an 1893 Marlin in .30-30 that I put a replica Hepburn sight on. It shoots high with modern factory, I have to set it at the lowest level. Cast bullet ammo I hand loaded shoot lower.
My trap doors both shot 18" high at fifty yards, they were zeroed for 250 yards!