8" gong or a paper plate.
This, or the NRA pistol target with about 6 inches of black.
All of my open sight weapons are purposely equipped with a flat top post front sight like that found on a Garand.
I find it effective to place the black dot just atop the post as in "Pumpkin on a post".
If I hold on the bottom of a six inch dot at 100 yds and the load groups in the center of the dot, that is my correct hunting elevation.
In the field, I envision the target's heart and set it on the top of the post. With the 260 Rem, for instance, that hold is good for 250 yds.
If one insists on using a bead front, it is usually recommended to find a contrasting color bulls eye of the proper dimension that one can see a complete ring of color around the front bead.
