the RIGHT to bear arms?

I recently ran across an article by some guy talking about the gun control issue, in which he stated multiple times "you have a right to bear arms, you have a right to shoot and if necessary kill anyone who tries to infringe upon that right. If federal agents come to confiscate your firearms, you have the right to use deadly force against them...." (Yeah, he kind of went on. guessing he is probably on a watch list now...)

Then two days ago, there was an article in our local paper about how all but one of Utah's sheriffs signed a strongly worded letter to President Obama, informing him that they would defend - with deadly force if need be - the second amendment rights of Utah citizens.

This article included responses from a few of Utah's ranking politicians. Some expressed the opinion  the Sheriff's overreacted, Others thought it was a political move, still others felt it was reasonable and appropriate.

There were a couple of statements that really caught my eye and mind. The first was an assurance that all of this 2nd amendment rhetoric was unnecessary as the planned action would only restrict a small number of firearms, and would not impact hunting in any way. The second comment was that the second amendment is difficult to understand or interpret.

For your benefit, here is the 2nd amendment in it's entirety:

"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. "


 (Note: There is noting in there about hunting. Not sure why they keep pulling that out.)

 It is one, relatively simple sentence. The first part is the justification for the second part. The justification being that, for a state to remain free it is necessary for the citizens of that state to have the means and the will to defend that freedom. I suspect the word "militia" was intentional. The men who wrote this were quite precise in their use of language. They understood the difference between an army, and a militia.

The second part is a clear and concise as you can get. Citizens living in the various states which make of the U.S. Republic are not to be prevented from obtaining and maintaining weapons of any form. If I have the means and desire to buy a tank, neither the Federal nor State government should prevent me from doing so.

Obviously, I have to use it responsibly once I have it, and if I fail to do so; if I become a threat to my neighbors, they have every right to use deadly force on me in their defense.

There is an implicit responsibility tied to this right. That I must be respectful and considerate of my neighbors. If having a tank parked in my front yard bothers my neighbors, I have a responsibility to find another place to park it. If I own a firearm, I have an inherent responsibility to learn to properly use and maintain it. I must learn the proper way to carry a firearm in public so as not to be a nuisance, or source of fear or intimidation. I must learn and follow proper procedure for identifying a threat, safely engaging said threat, and handing off control of the situation to authorities when they arrive.

But that first part is what really caught my attention, after reading the previously mentioned articles.
"A well regulated Militia, being necessary to the security of a free state...". "...being necessary...".

Is it really a RIGHT to bear arms? Or is it in fact a responsibility to bear arms?