Farming question

Unless my luck sucks, after using the reload command, do mobs no longer drop cores? i must've reloaded this map 20 times trying to farm diggers. I tried to do the reload trick on heavy warrior, and it didnt drop anything the second time i killed him, but i figure that may just be because hes a miniboss, but what about just regular mobs?

Don't know if its for EVERYTHING but I do know bosses don't drop evil cores if you reload the map.