Our backbores are designed to fit all cups with Warburton Style threads.  Models 1 and 2 are are our tightest backbores.  They are suited for Bb trumpets and Jazz, big band, and commercial work.  Numbers 10 thru 117 are progressively more open.  The number 24 with a 24 throat is widely used for C trumpet.  The 117 backbore is favored for piccolo.

The most important dimensions in a backbore are throat bore size and length, and the overall volume of the system.  The wider the throat the broader the sound. A longer throat makes the mouthpiece more stable at the expense of flexibility.  Backbores are listed by volume, from small to large.

The overall length of the backbore is 2.79".  With a standard Osmun or Warburton top the overall mouthpiece length is 3.44".

The threads are .375-40, .250 long.

• For clarities sake we use Vincent Bach's numbering system for our 10, 7, 24, and 117 backbores.  Since backbores are made with reamers each maker's are unique.
• Backbores can be made in any variation of tapers and throats
• We can thread your cup to fit our backbores or make your mouthpiece into a threaded backbore. 
• Call 978 823-0580 or email us for details. 
• Backbores with modified throats are non-returnable.