Original British Napoleonic Royal Navy Gunner's Cannonball Calipers from H.M.S. Northumberland (1798) colts The French had converted 358

The French had converted 358

the opening in the throat may need to be widened

30-06 rimless cartridge

There are 5 possible markings:

Original British Napoleonic Royal Navy Gunner's Cannonball Calipers from H.M.S. Northumberland (1798) colts The French had converted 358Original Item: One of a Kind Set. These are extraordinary, being British Naval Gunner's Calipers for measuring Cannon Balls aboard ship during the Napoleonic Wars. Measuring 26" on each leg, these measured the diameter of the large Cannon Balls, ensuring they are delivered to the correct sized Cannons from the Storage Magazines. One leg bears a brass plaque on one arm simply stating: H. M. S. Northumberland H. M. S. Northumberland was built in 1798 at