The bores of Rudy Meinl tubas, particularly the largest ones, have really huge bores (e.g., .866" for the 5/4 and 6/4 tubas).
Are these bore sizes measured the same as we would usually expect?
That is, the usual way to measure bore size is the inner diameter of the inner slide of the 2nd valve (right?).
I believe I heard sometime in the past that the Rudy bore sizes are measured as either the outer diameter of the outer slide. Is that correct? So even though it's still quite a large bore, it's not as crazy large as it seems when reported as .866". True or false? And is this just for the 5/4 and 6/4 horns?
Because the other Rudy tubas (like the 3/4 and 4/4 CC) are reported as more normal sizes (.768" and .730"), so maybe not.
