Hi Wyoduster,
You are not alone at all with having trouble forming the lock panels. We all have trouble in the beginning until we understand the best sequence of steps and can visualize how the contours should look. I teach this at Dixon's. For me, the first step is my drawing of the gun. That sets up the fit of parts and the final dimensions. Then I shed as much wood from the stock as I dare based on my drawings. Next, when shaping the lock area and wrist from a squared stock, I let the lock panels form naturally as I round the wrist and lock area. Those areas are not flattened on the bottom and top with the corners rounded off. Rather the lock area should look like a tennis ball with little flats cut in the sides for the lock and side plate. I am simplifying here because on some guns the top and bottom have slight concave profiles while on others they are fat balls. It depends on your design. In the process of shaping the round wrist and lock area, the lock panels form naturally. The only place where I cut them in with a gouge or chisel is the front of the lock. The photos below show the profile I usually try to achieve.
Once the panels are formed, I leave them and mostly finish the gun. Only when I am almost to the point of final scraping and sanding before stain, do I cut any lock panel moldings. If you want cove moldings with a tight radius, you can still do that. However, most original guns, at least from the 18th century, have moldings that largely conform to the general cross section of the stock. Below are photos of original guns and those I made showing different lock moldings. The common thread is that all were shaped during the process of shaping the wrist and lock area, and no moldings were cut until the gun was almost ready for stain.
dave
