I looked at a lot of pictures of old guns. The proportions that I went with are not normal, but they are historic examples. The proportions of the 4 bores are all over the place. Seems likely that every one was built to order in the 19th century. I am trying to stay historically accurate, but making it something that I can actually shoot is going to take precedence. What finally decided it was when I shot one of the larger modern elephant rifles holding it with the same hand position that would be used with a short fore end. Much harder to control that way. The 4 bore will have over triple the recoil of that modern rifle.
This rifle is definitely a challenging one. I am working on inletting the entry pipe right now. And the the intros. I am spending way to much time on the artwork for those, and having way too much fun with them!