Swifty,
I appreciate that, and I wasn't reacting to your post.
The problem could also be a combination of factors, not just one. In my experience problems with scope parallax (including such stuff as loose reticle cells, which don't always show up on every shot) and wind are two VERY common factors in group size beyond 100 yards. Wind, in fact, the the big reason for the myth that bullets lose stability at longer ranges.
Then there's the human element, which we just witnessed in the thread on light rifles, where one shooter shot tight groups and another shot scatters under the same conditions. Just because two shooters got comparable results at 100 and 200 doesn't mean those are the ONLY possible results.
