Ron:

1857 style, bronze Napolean smooth-bore which shot 12 lb. balls and was forged in 1863 weighing 1,186 lbs. It included the markings on the rim of the barrel : Serial # "47", "GWR" (George Washington Rains), "AF" (Augusta [govmt] Foundry).

This is the type cannons I am seeking. Thanks for the help so far.