1
Pick up the musket ball with forceps and examine it for a mold seam. Because of the crudeness of some 18th-century molds, the seam of an authentic musket ball may be slightly offset.
2
Hold the musket ball in the forceps and look for a round, raised bump on the ball. The bump, known as the casting sprue, was made in the inlet channel of the mold.
3
Examine the ball for a white, lead-oxide patina. Musket balls buried underground for years develop a coating. However, the presence of pine and oak trees in the excavation area can darken the sheen of an authentic musket ball to a deep reddish-brown.
4
Measure the ball's diameter. 18th-century musket balls range in diameter from 0.39 inches to 0.69 inches. The British Brown Bess musket carried a 0.693 inch diameter ball. American rifles took smaller balls, measuring less than 0.60 inches in diameter but no smaller than 0.39 inches.
5
Weigh the ball if its shape is not spherical. A fired musket ball may have hit a tree or other object and changed shape. Calculate the ball's diameter with the formula: Diameter in inches = 0.223304 x (Weight in grams) to the power of 1/3. Compare the calculated diameter to the measurements in Step 4.