http://www.chuckhawks.com/12gauge.htm
The principle drawbacks of the 12 gauge shotgun are the size and weight of the typical 12 gauge gun itself, especially the repeaters, and the recoil generated by the big shells. These two factors make the 12 gauge unsuitable for many shooters.
According to the Shotgun Recoil Table the recoil energy of a 1 ounce target load at 1180 fps in a typical 7.5 pound gun is 17.3 ft. lbs., about like the recoil of a .270 rifle. The typical promotional shell with 1 ounce of shot at 1290 fps in the same shotgun hits back with around 20.8 ft. lbs. of recoil energy, about like an average .30-06 rifle. These loads deliver about as much recoil as most shooters can stand on a continuing basis.
A typical high-brass load with 1 1/4 ounces of shot at a MV of 1330 fps fired in a 7.5 pound shotgun is much worse. It belts the shooter with 36.4 ft. lbs. of recoil. This is roughly equivalent to the kick of a .300 Ultra Mag. rifle. Average hunters should strictly limit the number of such loads they fire to avoid developing a flinch.
12 gauge Magnum shells are even worse. A 2 3/4 inch Magnum shell throwing 1 1/2 ounces of shot at 1260 fps from a 7.5 pound shotgun belts the shooter with 45.9 ft. lbs. of recoil, somewhat more than the recoil of a typical .375 H&H Magnum rifle shooting 300 grain factory loads! And the 3 inch Magnum 12 gauge shell firing 1 7/8 ounces of shot at a MV of 1210 fps in that same 7.5 pound shotgun slams the shooter with over 60 ft. lbs. of recoil energy. This is equivalent to the recoil of a .378 Weatherby Magnum rifle, and exceeds the recoil of a typical .458 Winchester Magnum rifle. This is literally recoil in the elephant gun class, and most shooters would be well advised to avoid such loads.
The make escapes me now but I think it was probably a Cooey or Winchester. It had no recoil pad and I remember as a teenager after 2-3 shots when duck hunting it was just too painful to shoot anymore and we had to take turns and hand it off to someone else.
