Springfield Model 1840 flintlock musket
The Springfield Model 1840 was a flintlock musket manufactured by the United States during the mid-19th century. The .69 caliber musket had a 42-inch (110 cm) barrel, an overall length of 58 inches (150 cm), and a weight of 10 pounds (4.5 kg).
Source: Wikipedia — Springfield Model 1840 flintlock musket (CC BY-SA 4.0)