That are beauty Mark, well done.
A few weeks ago I got to hold a double .500 nitro express rifle, the bugger wouldn't let me take it home.
My first encounter i thought it was a large shotgun till i broke it and saw that amazing rifeling down the bore....same day i got to shoot a 454 Casual and a 7.62 pistol......happy days.....not shot a .500 either......470 is the closest