I am against this.
But it should be noted this is actually not quite the violation of the Constitution that many people think it is.
I recall members of the militia, being all able bodied men between a certain age (and now we are a society of equality so that presumably would include women too) having to report with arms.
The Uniform Militia Act in place for a long time in the United States actually required it by federal law.
There was just no punishment for non-compliance at the federal level, but it was the law.
Militia members were to arm themselves with a musket, bayonet and belt, two spare flints, a cartridge box with 24 bullets, and a knapsack. Men owning rifles were required to provide a powder horn, 1/4 pound of gun powder, 20 rifle balls, a shooting pouch, and a knapsack.
This was when such arms were the standard arms of professional infantry.
The modern equivalent would be every citizen having to at least have an M16, with so many loaded magazines, and minor cleaning supplies.
The roots of this system (separate from the roots of the right to keep and bear arms) are stated in this portion of an article:
The American militia system has its roots in ancient English tradition, dating back to the Anglo-Saxon militia that existed centuries before the Norman Conquest in 1066. This militia, known as the fyrd, consisted of every able-bodied male of military age. It was traditionally used for defense only, and the sovereign could call upon the fyrd to fight if the men would be able to return to their homes by nightfall. Fyrd members were required to supply their own weapons, which they could use only in the service of the king.
It was essentially a short term defensive force that could not be deployed anywhere, but could be required to assemble for defense.
Sending such men on offensive tasks or abroad though would have been unheard of.
The individual RKBA stems from later things such as the Magna Carta. Where rebellious barons made sure they retained the RKBA so they could battle the king's forces again in the future if needed. Essentially a check on tyranny by protecting the right of free men (which were a minority in the feudal system) to weapons that would allow them to effectively fight their own government if necessary.
Later being partially extended and influencing the right to arms of many more people in the English Bill of Rights.
The Magna Carta principles were combined with highly respected thought from individuals like John Locke and "natural rights" to insure the right of individuals to arms.
So a requirement to own arms was in fact considered Constitutional by the very men that wrote the Constitution.
The US Bill of Rights was written in 1789 and ratified in 1791, the Uniform Militia Act was passed by many of the same people in 1792.
They clearly felt it was Constitutional to require individuals to own arms of the type necessary for modern combat of the day. (Is that a "sporting purpose"
? )
So summed up:
The Requirement to keep combat arms historically stems from a requirement to have the capability to fight for the government in a localized defensive manner.
The Right to keep and bear arms historically stems from the right to retain the capability to fight against the government, and later applied to other self defense and self preservation applications.
Combining the two would leave one with a requirement and a right to keep arms capable of being effective against typical forces, including those of foreign and domestic governments, and a right to bear them.
