That got me curious Sabotloader. So I pulled my X7 from the rack and measured the barrel wall thickness between the bottom of the grooves and outside of the barrel, at the top and bottom and right and left sides. Here's what I got after double checking each measurement at least three times.

Top = .152
Bottom = .152
Right = .149
Left = .151

I wasn't sure what that was telling me other than either the bore or the outside of the barrel is not perfectly round. So I measured the outside barred diameter 1/16" back from the muzzle and got .810 top to bottom and .811 side to side.