My reply is about the same, just worded differently:
Presuming you have the conventional sights as I have, here's what to do:
Set a target out at 40 yards more or less.
Use a large cross so you can see a good consistent aiming point.
Set the rear to the lowest position.
Place the front bead in the bottom of the rear notch and on target.
You should see a complete circle just touching the each side at the bottom of the rear notch and equally on center up /down, left / right.
Fire
You should be low.
Adjust rear sight one more notch higher.
Fire again.
You should be an inch or two higher, but still too low.
Adjust once more and you should be closer or on target.
Now go out to 80 or 100 yards and see if you are high or low then adjust as needed.
My point is that the hits and adjustments should fall into sync and make sense.
If not then you may be holding the rifle too high or low.
Sight radius is also a factor. One rifle may be longer or shorter and that can make one rifle have a different setting than the other. My sight radius is 17 inches.
If you sight in at 60 yards with the buckhorn and front bead, I suggest you make your cross target with 1/2 inch or 3/4 inch wide black electrical tape.
Put it on white paper or cardboard. Sit at a stable shooting bench for best results. Use a good rest up front for elevation and at the butt as well for stability. Relax, squeeze with a solid steady aligned hold. Don't give into temptation to shift your point of aim for the next shot. Use the identical sight alignment and sight picture. Adjust the rear ramp from lowest then up enough to get there. If you are not sitting at a gun club shooting bench, then make the best rest you can out of what is available. A tree limb, truck hood, shooting sticks, etc.