Tight gun control in Australia, an example for the US?

                                                                                              (C) thegunstorevegas

The U.S. has been shaken by multiple high-profile mass shootings in the past few years...an elementary school in Connecticut, a movie theater in Colorado, two separate incidents in Fort Hood, Texas, and now the church shooting in Charleston, South Carolina.
If Australia can implement sweeping gun-control measures that have been successful for nearly two decades, then theoretically it's possible in the U.S. However, this major decision is limited by the factors that are deeply rooted in its culture and baked into its founding document.

So, how long do we wait before something is done? Or who would be the next victim?
Culled from an article by Laura Smith-Spark, CNN