Harpoons also carry a warhead about 50% larger than the Neptune, increasing the range of targets they can effectively hit. The Neptune is only designed for targets of 5,000 tons, compared to the Moskva being over 10,000. Whether it was a lucky hit on a/the magazine compartment(s), poor damage control, or combinations there of, good job Ukraine and the Neptune.
Because missiles are not a renewable resource, and the more they have the more they can fire?