I know this has been dealt with in past threads. Hell, I'm pretty sure I even asked this before, but I couldn't find anything with the SEARCH function.

Regulating a double rifle. How do you steady the weapon to ensure a straight, honest shot? I don't think you can even use a typical sandbag on a vise bench gizmo, so what do you need, and/or what do you need to do?

Sorry if this has been answered already a thousand times.