I have copies of two of Baker's books, ( Rifle and Hound in Ceylon and Wild Beast and Their Ways) in both when he writes about a ten bore it's in reference to doubles. His faforite rifle for large game was made by Gibbs, weight of 21lbs,1oz. of powder, and 4oz. bullet. He also mentions exploading shells and steel caped projectiles both being conical balls. If you can find copies of his books they make great reading and refrence material. I've read both many times.