Well I've posted all the details on the 12 Bore before , but to summarize the 12 bore is a top lever hammerless by Tolley 1896 , 3in most likely a 9Dram rifle , but no load data on the rifle , 1 in 80in twist , 24in barrels , 100 yard standing sight folding to 300 , almost 15lbs & semi visible rifling , actually the rifling is more than that it is rounded with sharp lands !

I have been shooting near 600Gr round balls at high 1900 to 2000 fps to try & get the barrels together , but still shoots 2in apart at 50yards , barrel groups are in the same hole most times , with the right load & I don't mess it up !

The 8 Bore is not put together yet , but will be a round ball rifle to at around 10 Dram level using nitro loads how ever & in plastic industrial cases for now , sized to 8 bore spec , twist is 1 in 100 , barrels will be 24in long.

I think I know now to make the moulds .005 over groove , but I suppose I need the ball round still after leaving the bore for aerodynamics ?

Thank you for the help .