I hesitate to offer my 2 Cents, especially amoung such learned company........but the Lord hates a coward....so here goes. Reading through this thread I couldn't find any mention that many hunting scopes are closer to parallax free at 200 than 100 yards.
If a scope had no parallax at 200 and 1/2 inch each way at 100 yards the farther groups are likely to be looking pretty good given an accurate rifle.This would account for some of these rifles shooting better than they should at longer ranges. Magic center-seeking bullets don't make sense. A bullet that goes to sleep may not continue to disperse at the initial rate, but how could it return to center? Some of the difference could be aiming error at 100, rather than increased accuracy at 200. Parallax and to a lesser extent focus could account for some of these cases.
To tack a question on a question are these claims ever made for iron sights? If so are aiming errors increased or decreased with distance with target style irons?
Dogleg
If a scope had no parallax at 200 and 1/2 inch each way at 100 yards the farther groups are likely to be looking pretty good given an accurate rifle.This would account for some of these rifles shooting better than they should at longer ranges. Magic center-seeking bullets don't make sense. A bullet that goes to sleep may not continue to disperse at the initial rate, but how could it return to center? Some of the difference could be aiming error at 100, rather than increased accuracy at 200. Parallax and to a lesser extent focus could account for some of these cases.
To tack a question on a question are these claims ever made for iron sights? If so are aiming errors increased or decreased with distance with target style irons?
Dogleg