A square load for an 8 gauge load of 2oz of shot would be 4 1/2 drams of BP. I would think an over powder card plus a cushion wad plus another over powder card would work well. Most old school loads for 10 gauge and larger professed F. I use FFF in my 12 gauge. I would try F and compare it to FF. On the wad column You might skip the cushion wad and just use two over shot cards to see how it patterns. You have lots of fun ahead of you figuring out what the old girl likes. I would get a good brass rod to load with as the guns ramrod might not be up to the abuse of range shooting. McMaster Carr has brass rods
https://www.mcmaster.com/brass-rods. I tapped the end of mine for a ramrod button
https://www.dixiegunworks.com/index/...+Ramrod+Button
Threaded Mode