Looks kind of like the Halo magnum, I think.
Also, I've made a gun that's not quite break action, but the top of the barrel opens up to allow blue rods to go in. It is single barrel, with removable stock and interchangeable shotgun grip/front handle. I then upgraded it to take a magazine (white/gray rods), but I think i like the first version better. Tell me if you'd like to see either version.