bonny, only Gamebore making black powder loads commercially as far as I know. Mainly 12's in paper roll crimp cases but they did make a few 20's and 16's in plastic cases. Very expensive!
As for light 7/8th. ounce loads look for Eley and Hull Cartridge Co. stuff marked 'Trainer'; nice light loads. Eley also make a sub-sonic load that is low pressure which they make for use in shotguns with sound moderators. Some other companies also market a similar type which are light on the shoulder. Lagopus.....
