My neighbor just bought a Moss. 500 this year, and the first day he patterned it, it looked like he got popped in the cheek with a set of brass knuckles. It was black and blue teh next day. He only shot 10 shells from a sitting(on the ground) position.
The following week, we went shooting again, this time I wanted to try his gun. But I fired it from a bench, on sandbags, with a sandbag over my shoulder. It never even nicked my cheek. He then tried it, and it didn' t his cheek either. So maybe you guys can try that while pattern testing your gun? His gun also has the factory ported barrel, and honestly, I didn' t notice any differnece between my 870 and his gun as far as felt recoil goes.
The stock design is part of it, his Moss. seems to be a bit low, almost making you peek up off the stock to sight down the barrel. I never had that problem with my 870. I even added a scope this year, but, I replaced the rear butt stock with a raised comb stock, to align my eye witht the scope. Haven' t been hit in the cheek yet with it that way either.
Mikey