Bigboar check your PM messages, Kiln Gun cases are the way to go, don't use the Gulandi or any plastic wads with BP, Fiber,Felt & I think Cork for that job, but lots of good tested Nitro loads out there, Blue Dot mainly, I have two 8 bore's only shoot a Tolley right now .

Winchester Industrial cases 6 drams FF=164gr BP, 2 1/2oz No3 lead shot, lighter load came with the gun but again lots of good nitro load info around & tested .

Remington cases are meant to be stronger/better but Winchester have been easier to obtain for free/cheap.