To wit: 'helice grip' means 'screw grip' or a cammed bolting system, if you will, as in 'inclined plane. What proof marks are present(?)and from where? Many of the 'helice grip' guns carry the 'triple proof' from St. Etienne, even though they are light weight guns; its more about the quality of the locking system and the bbls. strength than any suggestion they be shot with heavy loads ... rather, it is more a statement that they are QUITE sound & capable of withstanding more than the shooter, irrespective of his ammunition choice, if you care to put it in totally practical terms. You likely have a 'h***' for stout double that will make a dandy bird gun if it fits you or can be bent to do so.
Whots the rest of the gun look like? I may have it's cuz. A 'brother' would be numbered, yes?