It is a fairly common problem..not only with this brand,but with the design in general..You might try to open it by doing a partial disassembly..like removing the forend and pulling the barrel a bit forward as you try to break the action(I assume we are discussing an unloaded firearm here!) If this simple act doesn't do it..then it should be returned to the manufacturer. Rossi warraties their product line for its lifetime. You can contact Rossi via
www.rosiusa.com for instructions Their physical address is: Rossi 16175 NW 49th Ave. Miami,FL 33014 Ph#(305)474-0401 if there is a local warranty center....you can find that info on their website