i recently bought a mossberg 835 and wanted to mess around and do some clay shooting with it at the local range. i have 4 factory tubes which are xtra-full full and one says mod-T&F Steel-I.C.-all lead- and another that says mod 2 & bb Steel-All lead.im guessing that those last two are improved choke and modified? i will be shooting winchester super target 12 gauge 2 3/4" 1oz 8 lead shot.