A couple things about the 8 gauge.
Parker made several thousand 8 gauges and a smattering of 6 gauges. Most of these went to market hunters, who used them to pick off cripples after use of the punt gun. Punt guns ran up to 2" in diameter, were fastened to boats and resembled artillery more than shoulder fired arms.
Market hunters varied greatly, like any other group, but man for man they were tough as heck. Many worked outside all year, fishing, crabbing, oystering and hunting as the seasons changed.
And they could shoot well past the commonality. Such men, combined with the heavy doubles and slow powders of yesteryear, meant the recoil forces were just something to deal with.
One such man, in his seventies when I was a boy, handled a 10 gauge double and shot it like Jupiter hurling lightning bolts. He had his dad's punt gun mounted on the living room wall, and could seduce geese from over the horizon when he called.
We see few large gauges these days because they were regarded as tools, taken care of but not pampered. After they became illegal for geese, many rusted away in barns and boat houses.
Often loads like this one were used to flock shoot on rafts of geese, with lighter loads used for single birds. One loading I saw was 1 3/8 oz of 3s for big ducks like canvasbacks or geese over decoys.