To figure out their likely time-period, it would help to know the state (and nearest town) where you found them.
By the way, buck-&-ball cartridges were made in .54, .58, and .69-caliber. Using the ruler in the photo for size estimation, none of the three balls in the photo look ike they were bigger than .50-inch in diameter before they were smashed. We need a precision weight measurement, in grains (not grams or ounces), for each of them, because knowing their very-precise weight can tell us the original diameter of a smashed lead ball.