Hellmuth's Mole;342368 wroteYou think nothing has changed in the last 20 years? Unreal.
Sheer numbers alone. The advanced "killability" of the automatic weapons being made today. The change to laws that allow "gun shows" ease of sale rights that stores don't have. And the only gun laws Mr. Anti-Gun president Obama has signed has expanded gun rights.
EDIT: Sorry, also forgot about the prevalence of on-line ammunition and gun sales....obv a bit different from 20 years ago.
The advanced 'killability'? Well, considering high powered machine guns themselves have been around in close to their present form for what....70+ years....I think those guns have and always have had plenty of killability.
Gun shows? Again, you are talking about availability that has been around for decades and decades. You think the laws regarding gun shows were more strict in 1965? I'm guessing back then someone would have had a very easy time of piecing together a military weapon and using it for all sorts of mayhem if the idea was planted in their head and they were in a state of mind that many of the nuts today are.
As for on-line ammunition and gun sales, you are getting to the point of the problem....the internet and media and what it is doing to society is a major reason why these things are happening....but availability of guns has very little to do with it :-[