America has a serious problem with guns; it seems like a mass shooting happens every other day. While politicians refuse to enact meaningful gun control measures, thousands of Americans die from gun violence every year. However, limiting access to guns will not address the root cause of the problem because it's not the gun that actually kills the person it is aimed at, the bullet does.
Bullets are what give guns their terrifying power to kill people. Someone armed with an assault rifle and plenty of ammunition can quickly murder dozens of people without much effort. If the bullets are removed from that situation, then the gun is about as effective as a large hammer at killing people. The gunman might be able to beat one or two people to death, but he's not going to murder 49 people and injure over 50 more like Omar Mateen did in the Orlando shooting.
Guns are incredibly effective weapons because the bullets they fire travel at extremely fast speeds. A bullet simply cannot be outrun. However, someone under attack from a knife-wielding assailant can escape harm by running away. If running away is not an option, the victim still stands a chance of fighting off the attacker. The same applies to baseball bats, hammers, or any other weapon that isn't a gun; there's a chance that you can fight off the attacker or run away. With a bullet, the victim might be dead before he or she even knew they were under attack.
Limiting access to ammunition makes it much harder for individuals attempting to commit mass murder to succeed in carrying out such an attack because ammunition can easily be hidden. It is much harder to hide an assault rifle in your jean pocket than it is to hide a clip of ammunition. It is far harder to stop a gunman armed with one gun and hundreds of rounds of ammunition than it is to stop one with three or five guns and only 20 rounds per gun.
Ammunition should be treated the same way as controlled substance medications like OxyContin or Adderall. You can buy a limited quantity of it if you pass a background check and other reasonable safety checks, but then you have to wait a period of time before you can buy more. After all, it makes sense that something that is designed to kill people be at least subject to the same regulations as a drug illegally used by some college students to cheat on final exams.