Yes, we have a lot of firearms, pretty randomly spread throughout the population and area of the country (with some notable exceptions). Of course whether or not this is 'a problem' or simply the way the US works is in the eye of the beholder I suppose.
And there are other, smaller genies waiting in the wings that you may not even be aware of in the UK.
The first thing is that a 'firearm' must be defined, and we have done so in the US by calling the 'part' that carries the serial number, usually the frame, "the gun"; all the other parts are simply machine parts that are not in any way firearms. So let us take the so often talked about AR-15 rifle for example; it is the lower receiver that is the 'firearm', with the great majority of the parts of that particular piece of hardware, including the difficult to manufacturer as well as the heat- treated parts [not] being part of the firearm. That means one can buy, own, sell, make, alter, possess or anything else, any and all of the parts of an AR-15 except the lower receiver.
Bear with me, I am going somewhere with this, I promise. Now, that lower receiver starts out as a block of aluminum, which is clearly not any part of a firearm but then goes through a manufacturing process to become the receiver that IS the firearm, and that part is regulated. But at what point does that piece of aluminum become a receiver? It is when it moves past the 80% point of the manufacturing time that it takes to make one. So, make an AR-15 lower but leave out the fire control group holes, leave a portion of the inside un=machined and it is NOT a receiver and firearm.
With the advent of CNC controlled machinery, and the refinement and general miniaturization of these machines over the years, they have become quite small, relatively inexpensive, and depending on software, easy to use. Now a complete 3-D milling machine needed to turn an 80% lower receiver into a 100% lower receiver is less than $1,000, not regulated in any way (hey, it is a machine tool, like a drill press) and can be set up to run on anyone's kitchen table.
So, tomorrow morning make "assault rifles" illegal in the US and an entire cottage industry will crop up to supply them illegally anyway. Oh there will be no where near the number being sold today, that is a fact, and statistically it would look great: AR-15's being introduced to the civilian population would drop by 99.9% but any gang- banger or worse yet, anyone hell- bent on doing great damage will be able to get one from some local 'back yard' operation. Sure the gov't will shut down and arrest those doing this, but others will spring up and just continue along. It will be like the US's War on Drugs, which ain't goin' all that great either: we intercept a huge amount of illicit drugs coming in to the US and those who supply them just ship even larger quantities.
So as you correctly point out Mike, the genie is long out of the bottle and has spread to all the corners of this country, there are other, smaller genies waiting in the wings to become a serious problem. Removing the firearms such as was done in the UK and Australia simply is not an option in the US, at least not one that would be effective for decades or centuries, but there are now other ways that will easily supply that incredibly small part of the population that is actually causing all the firearm issues.
That leaves population controls or as maxtog suggested, changing the 'hearts and minds' of those few who are causing all of the violence. Changing the hearts and minds, or at least identifying the problem individuals would be best but is also the most difficult and given our Constitution, it would be difficult- to- impossible to 'stop' those deemed a threat anyway. Which leaves controlling the population as the only thing that has a chance of working; more security, less personal liberty, traded for less violent outbursts.
Brian
As stated previously elsewhere (& which I don't think you would necessarily disagree about) the problem for you guys is that the genie is out of the bottle as far as guns are concerned. All you can do is try & chip away at the problem. Sadly there is no quick/easy fix.
<snip>