Hi Folks,
It is very hard to compare the mahogany likely used in Haines' rifle and the mahogany we have available today. In Haines' day, the wood was almost certainly-old growth, not plantation grown, and most likely Swietenia mahoganii commonly called Cuban mahogany. Cuban mahogany was almost logged to extinction and today we usually buy Honduras mahogany (Swietenia macrophylla. The combination of old-growth and the species mahoganii could easily produce a heavy, dense, and strong stock that worked more like red maple than modern mahogany. Here are some data showing specific gravity of dried wood and Janka hardness: Honduras mahogany - 0.59, 900lbs, Cuban mahogany - 0.60, 930lbs, red maple - 0.61, 950lbs, sugar maple - 0.71, 1450lbs, black walnut - 0.61, 1010lbs, English walnut - 0.64, 1220lbs, black cherry - 0.56, 950lbs. Also, if the lumber was from old growth, all of those values would increase significantly.
dave