Ho riportato solo quello che c'era scritto nella Loyalist, cmq mi sembra che la 6310 ha il canneggio m, la tua dovrebbe essere ml. Comunque riporto direttamente dalla Loyalist
Nearly all of the early Yamaha trumpets had clear Schilke design influence and, though that relationship has been over for almost twenty years, the Yamaha professional lightweight trumpets still bear very clear relationship with their Schilke forebears. For example, The Yamaha YTR 6310Z began its life as a copy of the Schilke B6, a medium step-bore design. Though the Yamaha has been through several models (the YTR 732, YTR 636, 736, 6310, 6310B and the 6310Z) it remains visually identical to the Schilke with the exception, of course, of Schilke's trademark hexagonal valve caps, buttons, and braces. Yamaha mouthpieces share the Schilke labeling system. The Yamaha trumpet line also included copies of the B5 and X3 for almost 30 years.
