I guess the basic concept and design was based on Winfer's book on the Farquharson (Vol #2), but particularly on the article in DeHaas book "Single shot Rifles and Actions".

The layout was based on a block of 4140 that I had, which already had a square hole EDM cut in it. Couldn't let it go to waste....

The "numbers" were worked out on Autocad on my PC abacus.

This was my third attempt - Check a thread on here called "Building a Henryish Rifle" for #2 - worth a chuckle.

Dumb, but learning...Prof Em, BSc(ME), CAE (FYI)