Let's Break It Down.

       Do you know what the second amendment to our constitution says? Here it is. "A well regulated militia being necessary to the security of a free state, the right of the people to keep and bear arms shall not be infringed." So conservatives are correct that we can't take away peoples guns. At least partially right.
       The amendment, if you read it carefully, states that the reason people have the right to keep and bear arms is in order to have a militia to protect their rights. But it doesn't say any old militia. It says a 'well regulated' militia. Now that makes a difference. You can't have a well regulated militia if you don't know who belongs to the militia or even what kind of guns they have, now can you?
       So it sounds very much like the government has the right to regulate the militia. The government can't stop you from being part of the militia, unless you have proven yourself to be dangerous to the people and their rights. The government can also regulate what kinds of firearms you can have. It just can't stop you from keeping and bearing any guns at all.
       So if the government decided to provide you with a militia uniform to wear when you bear those arms, I suppose they would have that right. In order to have the militia be well regulated, it might reasonably require that you have a certain type of firearm. That way it could more easily supply you with ammunition. By the way, the second amendment never mentions the type of magazine or capacity thereof, now does it? So large capacity magazines aren't protected by the second amendment at all.
       Actually for a militia to protect our rights from a government gone haywire, we need to be allowed to keep and bear all sorts of firearms. But in order to protect the people from individual unstable militiamen, we do need to limit some types of firearms to the active army.
       Ya see? If you just read for comprehension, you get to understand why the second amendment is so important. It clarifies why you have some rights and why those rights can be regulated in common sense ways for the good of all.