I respectfully disagree that patterning a wingshooting gun is a waste of time!
Had I patterned mine goose gun I'd have saved lots of money in shells and less cripples. Even just one shot on paper would have saved me lots of time and money.
My case: I bought a Mossy 935 to goose hunt with. Took it out and missed goose after goose or crippled them up. This went for several trips. I was thinking well its just me not getting the lead right, maybe the wrong choke for the situation? All I knew was I was missing and or crippling geese.
So I went and set up a 4ft x 4ft target and shot the gun at 20yds. It was hitting over a foot low at 20. Took another out to 40yds and it was over 2 1/2ft low! That gun went down the road. 2 shells and 20 minutes of my time was all it took to realize this thing shoots nowhere near point of aim.
Next shotgun I bought (not for goose hunting) was the CZ Bobwhite and with memorys of the Mossy 935 still etched in my head I went down to my pond and picked out a leaf floating on the water. Shot and saw it was centered with the right bbl, picked out another and shot and saw it was centered with the left bbl. 2 shells, 5 minutes and I was done.
I sure wish I had shot the Mossy 935 before I went out on a shell wasting goose crippling series of hunts. I'd have saved lots of money in shells, geese from crippling wounds and the frustration of wondering why am I shooting so bad.
I guess I could have took it to the skeet range and shot up a box or two of shells and figured out it was no wingshooting gun. Then went and patterned it and found out that it shoots way low to point of aim.