As people from Europe began exploring Africa in the early 1800s, guns were made to handle the very large animals that people saw. This was for people to protect themselves, to shoot animals for food, and later, and most commonly, sport. The first guns were the simple shotgun designs already used for birds. They were loaded with solid balls of lead that could shoot large animals. Because they did not kill large animals very easily (some writers said that it could take up to 35 shots to kill one elephant), elephant guns were soon made into larger caliber black powder smoothbores. The caliber was still measured in bore or gauge - or the guns were named by how much the projectiles (what was shot out of the guns) weighed in ounces. The projectiles were lead round balls or short slugs shaped like cones. Sometimes, antimony was put in them to make them harder.