Austin Custom Brass

Austin Custom Brass Prototype Backbores in Raw Brass

(3 reviews) Write a Review
ACBTPBB Prototype Backbores
0.50 LBS
Calculated at Checkout
MSRP: $95.00
— You save $45.01


I've been experimenting with some new backbore designs to add to our ACB line. Right now I'm offering them at an introductory price, in raw brass (we can silver plate at an additional charge, just send us an email). There are three new sizes available, and they're all a bit different from our current offerings. The brass has a higher copper content and the interior dimensions are different from any of our current production backbores. The sound shapes with these backbores are a little richer and thicker.

Basic comparison info:

  • Small: Somewhere between a Bach 76-85, a tighter commercial style design
  • Medium: Similar to a Bach 10, a more all-around design
  • Large: Similar to a Bach 24, orchestral style design

All come standard with a 27 throat (can be opened on request). These have the same "Warburton" threads as the rest of our two-piece mouthpiece parts, and they're compatible with tops from many other makers as well.


If you have additional questions send us an email

Prior to ordering please check our Shipping and Returns policy.

Also note weight indicated in the ad is shipping weight not actual weight of item.

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3 Reviews

  • 5
    prototype backbores

    Posted by Gary on 7th Feb 2022

    I found the small prototype backbore to be excellent. I bought a large and a small. I liked the small so much, I bought a second one the following week.

  • 5
    Medium backbore

    Posted by Mark in Calgary on 8th Jan 2021

    I play on a medium large backbore for most playing, with a medium small for lead. I was looking to try something in between, so I gave this prototype medium a try. My first impression was that as I ascended to the top of the staff and beyond it was a little tight, and I wasn't sure I was going to like it. I soon realized that I was working against it, and just needed to back off and let it do the work. The sound is pleasant and rich. The biggest surprise for me is above high C; notes are easy, with a big fat sound and snappy articulation. Bonus!

  • 5
    Awesome Backbore...

    Posted by Scot McPhetrige on 29th Dec 2020

    I matched the Large backbore with an MV 1.5 acrylic top. Wow! The tone, response, and clarity of articulation are incredible. What a bargain on this backbore.

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