Would there be any issues with chambering a .416 Rigby on a High Wall action? I know there would be an extractor issue with it, but was curious about the strength.

I wouldn’t build a Rigby on an original action, but one of the modern copies like the Browning would be fine; just don’t ask me to fire it. The large amount of drop at the heel required by the 1885 design makes recoil and muzzle flip much worse, at least for me it does.

Thanks John! You are correct if you build on the original pattern, but if using a pistol grip and a higher comb line you can deal with some of that flip. Doesn't look bad either.

If you do the math the chamber walls are mighty thin (I get very close to .125"). A little better with a more recent Winchester/Browning 1885s (the threads are finer), but still probably below what any gunsmith would call safe.