for those that don't visit the doublegunshop forums
One of the British posters recommended a new book by Diggory Hadoke titled 'Hammer Guns in Theory and Practice'
since i have enjoyed his other books and this topic is of special interest to me - I went out and ordered a copy on Amazon.
https://www.amazon.com/Hammer-Guns-P...nd+Practice%27.
its available from many sources
I'll post a review once it arrives and I get to read it, but i figure some may not want to wait (or care what i think
)