Actually the Bill of Rights (1689) enshrines the right of Protestant citizens to bear firearms.
It is most definitely not related to any kind of militia but the right of relatively affluent citizens to defend themselves from thugs and highwaymen and for gentlemen to engage in duellling. The idea was a landowner could carry a small short range firearm if he should be walking the streets at night with a purse, which were finally lit in London in 1680 for similar reasoning.
By contemporary reasoning it is the right for stable, law abiding citizens to engage such sports as shooting, and keep shotguns on their estate without too much trouble, or for a wealthy gentleman to defend himself against a home intruder with a Webley in between hunting trips to Africa. It's nothing to do with shoe salesmen and auto mechanics running around on the street strapping 9-mils shooting up criminals for example.
You must understand the cool thing about the parliamentary system is you can't repeal their authority with say constitutional law for example, it doesn't work that way, you can't wave a document in their faces and tell them how it must be interpreted, they'll tell you how it is to be interpreted and generally speaking will do so by examining it "in context as to the reasonable mind."
But then, where examined as a historical document neither is the US constitutional ammendment relating to the "right to bear arms," as it was a State right by intention and for the formation of State controlled militias beyond the authority of the federal government and aside national militaries, it had nothing to do with individuals either defending themselves from criminal activity of any kind, nor running around on the street bearing arms for giggles and inherent stupidity.
Certainly it is used in modern times by lobbyists and individual citizens alike pertaining to individual self defence and vigilanteism however this was clearly never the intention of the document. But then American culture has evolved with ridiculous laws like justifiable homicide, where modern parliamentary legal systems and commonwealth culture observe that homicide is never justified, ever, but it is occasionally unavoidable. Big difference in perspective on the matter.
If the United States was governed by a parliamentary democracy there is no way on earth they would allow the constitutional ammendment in question to be interpreted as a common right for citizens to bear arms wontonly or whimsically, it would enshrine the right of individual States to form paramilitary militias for use by State government officials in the event of dictatorial and oppressive federal government (ie. inadvertant neo-Nazi national election) only. And they wouldn't be using concealed handguns, they'd be using F-16's. It was meant to be State controlled national guards.
It must be recognised that Americentric and Eurocentric views on the entire subject are culturally at odds. Entirely different perspectives on what a democracy entails are being practised and have been for hundreds of years.
The yank way is very bad in terms of proliferent deadly crime pro rata. The same guy that bottles a feller down the pub in the face in England shoots six dead in the US and then starts on a school.