Please Guy's let's not put to much emphasis on the story, That was the sellers story & I discounted the story with the picture of the gun Goering holding being a boxlock and this gun being a back action! He didn't even know the calibre describing it as being a 9.3 and my preliminary investigation has been narrowed down to 3 calibres so far.
500/450 #2 Musket Black Powder
11.43 x 60R Martini
11.43 x 60R Romanian Peabody

.665 Rim dia.
.070 Rim thickness
.580 Base dia.
2.400 long
.455 Bore

These are taken with calipers as I haven't had the chance to chamber cast for exact measurements yet
The story connecting it to Goering is interesting in the sense that my Scherping .500 Express D/R also had a Goering story but I shrugged these off as sellers stories being as neither had documentation confirming the claims. I think alot of these stories were made up to try and capitalise on the value. I really wish this one could talk!

m4220