Roscoe, thank you for posting Jim's drawings for a standing rest. I think it is a most worthwhile piece of equipment to have, especially as nicely as Jim built them.

I have used a standing rest for a long time now. I believe these old double and light magazine rifles do not shoot as they should, either group wise or point of impact, if shot from a bench rest. They are hunting rifles, and a typical supported hunting shot needs to be replicated. The recoil from a heavier calibre is also easier to take with a standing rest.

If you don't have one already, I'd encourage you to build one like Jim's.