Miller, I found the Fergus artice: "Short Chambers & Steep Cones", Shooting Sportsman, May/June 99. (Further information on the gun in question in "Iron & Steel Intertwined" in the same issue.) The gun in question was a Westley Richards made in 1894; passed reproof under the 1954 rules of proof. He had the gun looked over by Alfred Gallifent, who apparently did not comment on the cones and what they might mean as far as choice of ammunition goes.