Quote:
Originally Posted by Schwab  Zeuster is right, but it isn't recent info, those have always been Bach specs. |
According to the Bach site, the ML was not originally the 0.459" it is today, but that is going back into the very early serial numbers. A brief snip from bachbrass dotcom, bachology article 6:
"Bach originally intended to offer three bore sizes: 0.448, 0.453 and 0.462 inches. He started out calling these bore sizes small, medium and large, respectively. It appears that very early in production, Bach decided to introduce an even larger bore size--0.468 inches. At this point, he had to decide what to call it. The authors think that Bach decided to call it large, but that meant he had to rename the 0.462-inch bore size. He renamed that one medium-large, and he continued with that convention for a couple of years or so. He stamped the second valve casings on the instruments made during this period accordingly. Trumpet #69 is one of these, a large bore trumpet stamped ML on the second valve casing. Some time later, Bach reverted to his original scheme and again began calling his 0.462-inch bore size large."
I apologize if my earlier post caused any confusion -- I have removed the erroneous information.