Many years ago I had a very long conversation with Jack Rowe a well known gunsmith in this country. Many of you know him. He ssid not to use a rest or a steady mount when patterering a shotguns. His reasoning at that time was this from what I recall
You snap shoot a shotgun, you do not aim it like a rifle. When you are aiming using a bench rest the sight is different that quickly thowing it up and shooting.
Many folks do not mount the gun in the same position each time when they throw it up. I have seen this myself in my shop. If you do not mount the gun cosistently in the same plase when you shoot, how can you determine where the gun shoots.
Maybe Jack is correct. What do you guys think
John Boyd
Quality Arms