god give you the guns you deserve, I think its a 577/500 No.2 rigth.
Is there a pressure test load for this round or do you copy 500 BPE loads , I believe this cartridges are very similar.
Do you use Bertram brass for it?
Came across a 577/500 No.2 last year on a gun show, the dealer was asking 10000 Euro. The gun was in the white, the dealer get it from the widow of an old gunmaker in england where it stand for maybe 60 years or more, never blued etc.
Dealer tells me 10000 are rigth because you will never find an old blackpowder double in the white again.
Was thinking that this was a piece with absolut no history, not worth the half of what he want but go my way.