I haven't notice this much as a factor. My Getzen is a 0.46 and my Kanstul a 0.410 bore. They both give me nearly identical response when combined with the right mouthpiece. Also in this TH link the bore of the mouthpiece with the bore of the leadpipe of the flugel is discussed. I believe this would be more of the factor in getting a full versus thin sound. Has anyone else noticed the price of the Kanstul 1526 has increased since they have been using this guy's picture? Kanstul.com ...or is it just me? No wait... it IS me!!!