I have handled them. They do not have a soldered rib. Instead there is a piece of rubber between the barrels. They have a manual cocking thing like the Krieghoff. After being reloaded, the S2 must be re-cocked, so it is a bit like using a hammer gun. The barrels can be re-regulated using set screws. The ones I handled had a high comb for a scope and it was difficult to get on the sights.