It had a diameter of 8 inches
Hailstones are usually irregularly shaped because of the way these are formed. The largest hailstone found looks like it was a conglomeration of smaller hailstones. That might be true. As the hailstone falls down it may merge with other hailstones and they become one. The icy nature of hailstones makes them stick together. Because the hailstones melt and freeze along the way, this process makes the hailstones stick to one another.