Identify the casting pattern of the ball. Authentic Civil War cannonballs will have three distinct mold markers. The most obvious will be a faint ring around the ball, the mold seam, where the two hemispheres of the casting mold met. The second mold mark will be a circular mark somewhere along the seam. This mark is from the filler hole spruce.
The last mark will be a circular casting hole 90 degrees from the mold seam. This ball has all three marking and is authentic! The item "Very Rare Antique Cannonball 3.5lbs 3 Civil War Rifled possibly Confederate" is in sale since Friday, July 07, 2017. This item is in the category "Collectibles\Militaria\Civil War (1861-65)\Original Period Items\Other Civil War Original Items".
The seller is "mantiques4you" and is located in Vero Beach, Florida. This item can be shipped worldwide.