If you want to play a mouthpiece between the size of a Bach 7 and a 1.5 you have to look at another source.
Bach makes 10 mouthpiece diameters that are smaller than a Schilke 6A4a. under 16.00mm.
Bach makes 8 diameters in the 16.00 – 16.25mm range. (Schilke sizes 6,7,8’s go here.)
(Schilke 9’s fill this empty Bach spot from 16.25 – 16.40.)
Bach make 3 diameters in the 16.40 – 16.50. mm. These are 2’s and are hard to find. (Schilke sizes 10 & some 11s go here.)
Bach makes 0 in the 16.55 – 16.95 mm range. (Schilke makes sizes 11, 12, 13 in here.)
Bach make some in 17.00 mm.(Schilke has the 14s.)
Bach makes 0 from 17.05 – 17.45 mm. (Schilke has some 14s plus the 15, 16 & 17s.)
Bach makes them in 17.50 mm. (Schilke has the 18s.)
Bach make 0 bigger than 17.50 mm.(Schilke has the 19s – 24s.)
Pops