Here's a fact. In 1965 I was 16 years old. I purchased a used Webley revolver and ammo by sending a check in the mail to a company that was selling surplus firearms. The gun came in the mail with the ammo and was put in our mailbox. We had a big mailbox because we were on a rural route and didn't want to drive to town to get our packages.
I now have about 6 handguns in my safe. I had to wait to buy just about everyone of those through an FFL and got delayed on the NICS check almost every time. It's really no different today than it was 49 years ago regarding the availability of firearms. People still have access to guns and if they want to use them to gun down a bunch of people they will.
As was posted above the Brady bill didn't change anything in any measurable amount and neither will a UBC. It was a feel good, do something now law. UBC supporters think that gov't regulation is the answer to all of societies problems and if you could just pass another law then everyone is going abide by it.
So I guess we get more legislation that has no effect other than having all of the people who normally follow the rules line up for more gov't regulation while all of the people that commit murder and mayhem continue to do so.
Personally I'm preparing myself for a UBC. I won't vote for it and I will find out which one of my representatives did and x them off of my good guy list but I feel it coming. Just another day in the life of a tax payer, voter, veteran, civil servant and law abiding citizen. The NSA, FBI, CIA and ATF can check me off their list one more time.