It seems that your patterns are pretty wide at 40 yards.
If you fired a single OO Buck load, how many of those pellets would hit a deer within 5" of your aiming spot?
In other words, how many would hit a 10" diameter paper plate at that distance?
Judging by the pic you posted, which I understand was for two shots (and thus has twice as many holes in it), I'm guess-estimating that only about 2 or 3 pellets would hit a 10-inch "kill zone" on the animal at 40 yards.
Even if 3 pellets hit your "kill zone" on the animal, that's only 3 pellets out of a total payload of 12 or 15, right? (You're using 3" magnum shells).
So, aside from adjusting your aiming point or how you use the sights / bead on those guns, I think you should test some tighter-patterning buckshot shells, or reduce your range to maybe 30 yards.
I never tested #1 buckshot in any ballistic media like gelatin, clay, or jugs of water.
But I did compare 00 buckshot to #2 and #3 buckshot, shooting soft pine lumber boards (several layers thick) at 15 yards, and I was shocked how little penetration there was with the smaller buckshot. I might use #2 for close-range self-defense against a burglar, but I was not impressed with anything less than 00 buck's penetration in pine boards.
This video shows a guy testing buckshot at 50 yards, and at that distance the pellets' velocity has dropped to 860 feet / second.
HERE'S A link to the YouTube video.
Take all the X's out to make the link functional.