Fyi, I belong to a UK shooting forum & one of the members posted a photo of the over/under EIGHT GAUGE muzzleloading shot-PISTOL that he built, as a “big lad’s toy”.
I cannot even imagine what the recoil of that BEAST would be like & neither would I want to find out by firing it.= 3 ounces of shot, in front of a heavy charge of FG black-powder in each barrel.
(He has also built & hunts waterfowl with a 3-inch bore PUNT-GUN, that is mounted in a 16-foot “gunning-skiff”.)
Yours, TMN78247
When I was managing a gun shop back in the early 70s we had a gunsmith who would testfire 10 Ga shotguns without a stock by holding onto the tang. . . Pointing them down range and pulling the trigger. Not something I would ever want to try.
He made himself a custom .460 Weatherby Magnum rifle that weighed in a little under 3 pounds. He had a standing offer that if anyone who paid him $50 to try to shoot it three times in a half an hour with a standard 525 grain magnum commercial load which produces 2600 FPS velocity at the muzzle. If they could do that, they could keep the rifle. He could do it, but he was 6’ 8” tall and weighed in at about 400 pounds, mostly muscle. A few people got in two shots in the time limit, no one ever tried for the third shot.
He let me shoot it once. I was a beefy guy weighing in at that time in my mid-20s, weighing in at over 250, and I padded my shoulder extremely well in preparation. I wound up with a big purple bruise up my neck and down my right arm and covering a good part of my right shoulder and chest for over a month from a single shot with that gun. I thought I had broken my shoulder. You could not have PAID me to try it again. . . Certainly not within a half-an-hour.
The recoil foot pounds on a 3 pound gun would be around 250 foot pounds per second. As a comparison, a standard .30-‘06 usually has a kick of about 18 to 20 FP/sec. A standard weight .300 Win Mag would have about 28 to 32 FP/sec. kick depending on load, and a .375 H&H Magnum, around 42-45 FP/sec. recoil.
When our gunsmith retired, he still had the rifle. . . But he had rebuilt it with a heavier barrel and more weight so it was about eight pounds and it had a more sane (?) ~100 FP/sec recoil. I still wouldn’t want to shoot it.