Interesting history, kuduae.
Conor, I found with my double 12, that both the 1550fps loads, 7 drams BP and the smokeless load shot the barrels well regulated.
Less loads did not shoot together. I had mounted an old 2.5-8X32 mm scope on the rib for load testing.
Tks for the info on tradeexcanada & Anthony.
I've never purchased moulds from www.tatvcanada.com. Last count, I had a mix of Lyman, Lee, RCBS, Ohaus & a Saeco mould, 82 sets of blocks all together, some given to me, I have never used.
I do have Tanner moulds in .595", .677", .704", .724" and .740". I also have the 16 bore Lyman mould at .662" & the Uberti mould at .682". That one looks every bit a Lyman mould and casts really nice balls for my 14 bore ML rifle.
I made an adjustable slug mould, casting thick skirt HB .690" from 580gr. to 1,200gr. These will fit nicely inside a plastic 12 bore shot wad. Too, I have 12 bore plastic wads that hold .58 calibre slugs. Got those from Ed Huble. Haven't heard or read anything by him in a long time.
SxS are not the best for waterfowling, due to the use of non-toxic shot. Steel or tungsten shot might be good for splitting ribs from the barrels at the chokes.
Buddy of mine had an old Belgium gun he shot steel in, only the right barrel. In 5 shots, it just expanded the muzzle, but the solder held. He said it still shot good for ducks over decoys.