Shot my 308 Savage 99 today at 25 yards and 100, open sights, 150 and 180 gr ammo.
Anyway, first fired a 3 shot group at 25 yards with 180 grain and 6 oclock hold.
Shots were dead on
Moved out to 100 yard and shot 3 more of the 180 gr, and they were 8 or so inches low.
Two notches up on the ramp rear sight got me in the black with more 180 gr and six oclock hold, and 150 gr hit about 4 inches low.
Moved back to 25 yards fired 3 shots each of 180 and 150 gr.
150 was about an inch low, and 180 was about dead on.
Did I just get a fluke group somewhere in the outing?
I've shot many rifles in the same ranges with both open and optic sights, and have never had 8 or so inches differance in POI between 25 and 100 yards.

Bullets go up before they go down

Check the crown
The forearm might need tuning.

But never above the centerline of the angle of the bore...only the angle of the sights.