The absolute number of guns may well be higher, but the percentage of Americans who own one is presumably far below what it was during colonial times, for instance. It is quite possible that the number of guns is rising but either a) new gun owners are not increasing as fast as the number of people or b) the number of gun owners is not increasing at all but existing owners are collecting more per capita than they used to. I don't know if that's the answer, but your argument that there are more guns than ever is a poor rebuttal to the grandparents argument that the percentage of Americans owning guns is going down.
Errr, we're wealthier, manufactured items are a lot cheaper, and it's a lot easier to keep a gun in working condition now that we're using smokeless powder and non-corrosive primers. Crime's a lot higher, I gather, so city folk have a greater need to be armed.
I don't have figures, and most of academia was delighted to celebrate a fraud who claimed very very few owned guns in colonial times (http://en.wikipedia.org/wiki/Arming_America) so data is probably hard to come by, but I wouldn't presume that at all.
