From an Old Better Homes and Gardens Heritage Cookbook. The narrative below is from there. When the ranch cook wanted to be especially nice to the cowhands he made a boiled pudding sometimes called Son of a Gun in a Sack. Raisins or dried apples and suet were added to a soft dough. Following the old colonial method, the mass was placed in a cloth sack and boiled in a big kettle of water until done. Perhaps it got its name because it was so much trouble to make.