Descriptions taken from the Pickett-Blackburn Website
Regular Length (Bb Length) 10 Series Backbores
These backbores have a more immediate increase in size after the throat for a more open feel.
10-2 (Similar to Wedge ML) - Our most popular classical backbore. The 10-2 creates a large sound without losing you with too much inefficient volume. This backbore offers that ‘classic’ backbore feel/blow that many have grown accustomed to. Applications - Orchestral/Symphonic/Soloistic/Chamber playing
10-3 (Similar to Wedge M) - This backbore offers slightly more resistance than the 10-2 without compromising the overall beautiful large sound. The attacks are more pronounced and speak quicker which creates a perfect mouthpiece for small group playing. Applications - Chamber Orchestra/Jazz Combo/ Soloistic playing
10-4 (Similar to Wedge S) - An extremely efficient backbore, offers a bright, focused sound. This backbore blends well for big band section playing without producing that strident sound known for lead trumpet playing. Applications- Jazz Band/Jazz Combo/Soloistic playing
Short Shank (C length) Backbore
OS - Designed for the orchestral player who desires that large/full sound that allows the player to use massive quantities of air without losing focus. Commonly used with #22-25 throats and deep cups. Pairs well with rotary trumpets. Applications - Orchestral/Symphonic playing
Trumpet mouthpieces are available with two standard throat sizes. #27 (.144 inch) is the standard size for most mouthpieces and best choice for most players. #25 (.1495 inch) is a larger throat for more open blow. Choose a #25 throat if your mouthpiece feels stuffy with too much resistance and you are an advanced player with good breath support.