What you guys don't realize is that most every barrel out there has a bow in the bore to some extent. This is because they're all drilled with extremely long, thin drill bits and the molecular structure of the barrel will affect the bit's path. The smaller the bore diameter the more apt you are to have a bit drift. In fact, I've spoken to a couple different barrel makers who have told me that only about 1 in 4 .17 caliber barrels make it out of the shop due to the bore being bowed or off-center at one end due to bit drift.