Heavy Signal Cannon on Base this signal cannon has a 1.75in diameter bore the cannon is 6.5in diameter x 8.5in long: has 2.5in diameter trunnions, measures 9.5in across the trunnions, weighs in at 70#, and has it's own steel plate base with trunnion sockets for the cannon trunnions a very early cannon and probably the heaviest we've sold as yet