I have a 16 Ga S X S with dubble triggers, 2 3/4 inch chamber . On the left side of the action ( SHOPLEIGHS KING NITRO ) On the right side of the action ( 5100 ). Stevens made the shotgun for Shopligh Hardware Company St Louis, Missouri which was in business from the mid 19th century untill the mid 20th century.. The parts book I have list the 5100 with the Stevans Mdl 311 side by side shotguns. It was commmon for Stevens to make guns for other companies.