Thinking about this from a centrefire perspective for a moment...

The top benchrest barrel makes try and get a barrel that is as dimensionally uniform as possible.

The air gauge their top barrels as part of the QC process and in the case of some manufacturers mark the most consistent as premium.

The do not guarantee that the latter barrels will shoot better than their normal barrels, which are after all from the same production lines, but point out that one is giving oneself the best fighting chance.

A few of them also mark the tight end of the barrel so that it ends up at the muzzle, we are only talking about 1/10000th here at most though.

It seems that as long as the bore of the barrel gets no larger, accuracy is not affected.

Therefore would choke be a traditional way of enduring this given that airgun barrels were made from inferior materials and not to the same standard as CF barrels historically?