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.
America has undergone vast changes, technology has undergone vast changes and we're still supposed to rely on a right created to reflect the needs of a time that's long gone?
Most of the weapons of that time were cumbersome to load, had poor inaccuracy and were in the hands of people who were tightly joined in the need for local self defence. It took about 15 seconds to load an 18th Century musket and required charging the powder, ramming the ball and filling the flash pan, wind and rain could make this difficult. Today with something like an AR-15 you could take out a squad of Minutemen before they could reload for a second shot. The pistols of that time were very inaccurate and in most cases one shot affairs, they were more for display and dueling than effective combat.
Now most Americans live in densely packed cities with serious social issues and there are millions of high capacity, rapid firing accurate weapons often in the hands of criminals and people who aren't emotionally or mentally equipped to handle them safely.
I also don't buy that having so many armed Americans preserves freedom in the country, the separate branches of government are
supposed to do that although the balance of power has largely been overcome by special interests like the financial, defense and energy sectors that determine who gets elected by how much campaign funding they get.
You also have a really screwed up electoral system in the US now with mostly electronic voting systems that aren't accountable and easily hacked, so how much freedom does the average US citizen have now anyway?
Black Box Voting - America's Elections Watchdog Group
There's just a lot of myths around freedom and firearms in the US, the democratic institutions that are supposed to enable a free American society have been largely circumvented so only a few people now have political and economic control of the nation. After the last Republican administration Americans lost a lot of their rights around privacy and the right to effective justice. So the 2nd Amendment is just an emotional comfort to some, not a real way to protect freedom.
More than a million Americans died of firearm violence in the last century, more than from all the wars fought, if firearms gave true security the US would be one of the safest countries in the world, but instead it's one of the most violent.
Hunters that claim they need the 2nd Amendment aren't being honest either. Who needs semi-auto rifles with 30 round mags to hunt dear, moose and bear? My step dad is a lifelong NRA member and long time hunter. He used to hunt bear from tree stands with
a bow. He also has friends who do just fine hunting deer and elk with muzzleloaders like the Hawkins replicas and others you can get. A five round .308 or 7mm is all the gun you're going to need for most game, there's bigger rifles for the truly massive game, but few people will ever need those. My stepdad also has a concealed firearms licence the he uses with his .357 revolver. If you need a semi-auto with a 15 or more round mag and you need a bunch of mags then you probably shouldn't have a gun in the first place. Take the high capacity, rapid firing weapons off the streets and you're halfway to a solution. No responsible citizen should need an Ar-15 or an AK-47 or even a Ruger mini-14. While it may be fun for some people to have and shoot these weapons it just gives too much capability to too many people who shouldn't have it. Limit handguns to revolvers or 6-8 round semi-autos. Restrict rifles to 5-7 round mags, hunters don't need more and go much above that and you're producing combat capable weapons.
Too many Americans are dying because firearms aren't being used as the 2nd Amendment intended, to provide security for a free state. Instead they're being used in many cases by people to kill themselves, settle scores, massacre completely innocent people, or to establish control of territory in organized crime conflicts. The US is in a state of chronic conflict with the huge amounts of firearms in the country.
The NRA has become a lobby group for the gun industry and shouldn't be listened to and neither should the firearms industry, it's shown consistently that it's only real interest is profit at the expense of thousands of American lives a year.
http://www.huffingtonpost.com/2013/01/11/nra-gun-control-firearms-industry-ties_n_2434142.html
Throughout its 142-year history, the National Rifle Association has portrayed itself as an advocate for the individual gun owner’s Second Amendment rights. In turn, the NRA relied on those gun owners, especially its 4 million or so members, to pressure lawmakers into carrying out its anti-gun control agenda.
In the last two decades, however, the deep-pocketed NRA has increasingly relied on the support of another constituency: the $12-billion-a-year gun industry, made up of manufacturers and sellers of firearms, ammunition and related wares. That alliance was sealed in 2005, when Congress, after heavy NRA lobbying, approved a measure that gave gunmakers and gun distributors broad, and unprecedented, immunity from a wave of liability lawsuits related to gun violence in America’s cities.
So the NRA and the firearms industry is just another group that has helped take freedom away from Americans, you can't even seek justice against them in court, one of the founding principles of American freedom.