Vidiot:
There's something fundamentally bizarre about a population arming itself to the teeth because it's afraid that its government wants to take away its right to arm itself to the teeth...
Exactly. And this is where your fundamental constitutionalists (the Timothy McVeighs) find part of their support and justification for contemplating terrorism.
There is another side to that irony you mentioned too, Vidiot. Some citizens (particularly the cons. fundis) demand the right to own military grade weapons in order to keep the government in check and criminals love them for obvious reasons. This then forces law enforcement to increase their firepower to compete with the population.
In the early years of law enforcement up until the early 20's, revolvers were the standard issue. In urban areas the .32 and .38 calibre revolvers were standard while in the rural areas the .45 calibre revolver we the prefered arms. Rifles were Springfield bolt actions or various lever actions. Side-by-side shotguns were replaced by 5 shot pump-action shotguns.
After World War One there was a huge surplus of .45 M1A1 Colt and Springfield (made under liscence for Colt) which the lenient government allowed cicillians access to. Unfortunately these found their way into the hands of criminals and law enforcement soon found themselves outgunned. This set a disturbing trend. Soon surplus Thompson sub-machine guns and Browning Auto 5 shotguns followed suit. This led the to the reign of terror by the notorious gangsters and bank robbers of the 20's and early 30's. Once again law enforcement was forced to up their firepower. Today civillians here complain about "military style" gear the police are equipped with but it is a direct result of the armament abailable to the general population.