Gun control is a touchy subject because most people only see the bad things they can do, guns can be used for good or bad things it's up to the person using them.
Most people would assume that buy controlling guns the crime rate will go down significantly, I disagree with this because the people who will have guns if they are illegalized are the people that are going to commit crimes. Murder rates will rise due to fewer people being able to protect themselves from assailants, making guns illegal will kill more people than it would save. Also guns are the main source of income for many people, if you take that away, people will lose their jobs, and some will be driven to crime, they will become so desperate to make a living that they will be willing to steal or sell drugs. However civilians shouldn't be allowed to own just any type of gun, you only need so much firepower to protect yourself, civilians shouldn't have access to any explosives, fully-automatic weapons, and there should be limitations on caliber to prevent over-penetration, after all we're trying to protect people not get them killed. Maybe certain people shouldn't be allowed to own guns, these people having a mental disorder that causes them to be aggressive or people with a criminal record.
Of course this leads to discrimination problems, should we discriminate? The answer is yes, if we are going to give people substantial power we should also give them the power to decide who gets the privilege of owning a firearm. The government should try to stay out of this situation as much as possible. Nobody wants somebody else deciding what they get, that's why we should let people decide in their state or community what type of firearms are acceptable, and what action is to be taken against someone who breaks those laws.
Why not design a special type of bullet? The problem with that is, if we're only allowed to use one type, there's isn't any room for free-enterprise and we could end up being forced to pay a ridiculous amount of money for a case of ammo.
Well wouldn't that cause people to be more reluctant to purchase firearms? Yes and no, the people that aren't planning on committing and crimes will most likely not want to buy as much, but the people who are will just find ways to get them cheaper such as theft, or just use illegal bullets.
So what should be done is civilians should be allowed to own any semi-automatic weapon that they want to as long as they don't have a criminal record, or a mental disorder that would make them overly aggressive, and that they follow their communities guidelines for what you are allowed to own. There should also be a limit on the caliber that civilians are allowed to carry, in most self defense cases you don't need to shoot through walls to get to your assailant you just simple need to shoot him/her. Once again this should be decided by the community or state the person lives in. If a person lives in a large city or other urban area the caliber limit should be much lower than it would be for someone who is out in the country and doesn't have to worry about over-penetration.

If they own it should they be allowed to carry it with them? Not always, I believe that a concealed handgun is enough to protect most people, but once again this is an issue that should be discussed in that persons community.