Quote Originally Posted by Stockrex View Post
the barrel can expand/move in any direction, not necessarily always up.
Could the POI moving up be attributed to increased speed of the bullet?
I would agree with you, except for when there's Devcon steel surrounding the first 3-4" of barrel underside. It was molded around the entire lower half of the barrel, so there was nowhere to go but up. According to the chronograph (and drop rate), there was no increase in velocity.

Once the under-barrel bedding was removed, the vertical stringing went away and fouling reduced.