The 3-pounder Whitworth rifle was a small caliber field gun deployed during the mid-19th century.
Designed by Joseph Whitworth, the gun was most notably used during the American Civil War.
Along with Whitworth's 12-pdr rifle, the artillery piece was considered for adoption by the British government's Board of Ordnance, eventually losing out to the Armstrong gun.
In service, the rifle was sometimes referred to as a mountain gun, though this might stem from a confusion over caliber sizes.
[4] According to a 1860 New York Times article covering Whitworth's weapons, the relatively small 3-pdr had superior range compared to his larger rifled guns.