...for a stock meant for mostly offhand shooting. Rifle is a .357 Magnum with an 18 1/2" barrel, ghost ring peep and front blade sights. I know I can fine tune it with wedges under the butt pad, but what angle is good to start from? Gil Sengel had an article in Rifle #246 and said that 83 degrees was about optimal. I exchanged emails with Mule Deer and John thought that 83 degrees might be too much, but didn't suggest a different angle and I didn't press the issue. Thoughts? Thanks in advance.

Start with 90 degrees and dry fire with different temporary shims and see. Keep your eyes closed and when steady open them to see where you are pointing in relationship to the aim point.

Even try some reverse pitch. It depends on body build and preferences so other than 90 degrees nothing is universal. Other option is a try gun but that might be hard to find although the representatives for the better shotguns have them.