Guys use them for geese and sandhill cranes a lot. I think they have lost popularity since the introduction of the 12 gauge 3.5" mag though. A 3.5" mag may have the same ft lbs of recoil as a .458 Win Mag, but shotgun recoil and rifle recoil are two different things. Rifles have a sharp kick, whereas shotguns have more of a push. I wouldn't think twice about the recoil of a 3.5" mag (or 10 gauge) being too much because the only time people use them is when they are hunting, and the adrenaline rush you get from shooting makes it so you don't even notice you're firing a gun.