OK, this may seem like a silly question, but can wingmaster and express barrels also be used on an 870 Police magnum? I ask this because I am potentially getting one or more and want to know if I can swap the barrels as I will be selling my only "field barreled" shotgun. I don't shoot clays much andthere is nothing I really hunt that requires anything but a slug barrel, but I am wanting to know if I can buy those barrels if the situation presents itself.