I recently picked up a ML bore Bach Strad "C" trumpet. Using the mouthpiece I use on my old Large bore "C" (Schilke 13C4) I cannot come close to playing up to pitch. With a 13A4 I can play to pitch, but just barely. The tuning slide must be pushed all the way in. Otherwise the horn plays well--good intonation, slotting, etc. The mouthpiece/receiver gap is rather large 0.207". It is just exasperatingly flat. Other than a shorter lead pipe has anyone got any suggestions about what might help this.