Diorio trumpet back bore (raw brass)

These are collector's items.
To my knowledge, they are not currently being produced.
These will fit any standard top (warburton, black, pickett, etc.)
These have been refilled and drilled to a #27
These have been cut to work with the Frost Screw Sleeve System.
If you don't have a Frost screw sleeve, they won't work.
If you need a screw sleeve, visit the Frost Custom Brass website.
I have these models in stock:
.003 H.D5 *7 41 53 DG3