List of muzzle-loading guns

Columns: Caliber ( mm ) | Weapon name | Country of origin | Design
64 | RML 2.5 inch Mountain Gun | United Kingdom | 1879 | 73 | 2.9 inch Parrott rifle | United States | 1860 | 76 | 3-inch ordnance rifle | United States | 1862 | 76 | RML 7 pounder Mountain Gun | United Kingdom | 1873 | 86 | Canon de campagne de 4 rayé | France | 1858 | 96 | Wiard rifle | United States | 1861 | 121 | Canon de 12 La Hitte | France | 1859

Example questions:
What is the muzzle-loading caliber of the weapon that was used extensively in the American Civil War ? | What is the muzzle-loading caliber of the weapon that was an artillery system designed to implement rifled muzzle-loading guns in the French Army ? | What is the muzzle-loading caliber of the weapon that is field artillery in the American Civil War ? | What is the muzzle-loading caliber of the weapon that was manufactured between 1861 and 1862 during the American Civil War ? | What is the muzzle-loading caliber of the weapon that was primarily used by the Indian Army ?

Answers:
73 | 86 | 76 | 96 | 64