FWIW in the 10 gauge weight department, I own a Darne 10 gauge that goes 7 pounds 3 ounces and an I Hollis 10 gauge hammer gun that goes 8 pounds 3 ounces. I handled a nice older W.C. Scott hammer gun last weekend that went 9 pounds 11.3 ounces. All three were 2-7/8 inch chambers. I'm guessing that there was as much variation in available 10 gauge loads 125 years ago as there is in 12 gauge loads today.