The FBI crime statistics clearly show that more people are killed every year by hammers and clubs than by rifles (in 2011, 496 to 323) http://www.fbi.gov/about-us/cjis/ucr...e-data-table-8
Better ban hammers and clubs, by the rationale of your friend. If he is going to insist on blaming the tool rather than the murderer, he shouldn't stop there - knives, fists, rocks, poisons, subways, cars - because the list is almost endless.
The fact is, we don't need to defend our choice of firearms. The 2nd amendment casts a very broad swath, and those who would like to limit the right enshrined therein (but only recognized by it, not created by it) through another gun ban bear the strict burden of proof, not we law-abiding citizens. Fortunately the USSC has reached several recent landmark decisions that are guiding lower circuit and appellate courts. "Firearms in common use" seemed to be the standard in DC vs Heller. After WW1, bolt-action rifles came into common use. After WW2, fixed magazine semi-auto rifles became highly popular. After Viet Nam, the AR-15 became highly popular and has remained so. And the term "assault rifle" is a political term made from whole cloth. Now, if belt-fed .50 caliber machine guns were being used on the streets, i'd concede the term.
I am formerly from CT, a town very similar to and not far from either Cheshire or Newtown. No one can downplay the utter tragedy of Sandy Hook, or fail to be moved to tears over the families and lives horribly ripped apart by the insane acts of that unhinged madman. But the acts of a single lunatic should not be enough to outweigh or impair the rights of millions of law-abiding citizens who by most estimates, use firearms more than 2 million times per year to stop violent crimes, usually without a shot being fired. Anyone who argues for a ban based on the "greater good" need look no further than that. I know it's callous, but it's true. And i can virtually guarantee that within those 2 million defensive gun uses, a lot more than 22 children's lives were saved from an equally tragic end.