DERBY - Local retailers Mr. O's and Wright's Enterprises have seen an increase in sales of firearms including assault weapons after the horrific rampage in Newtown, CT, last week. Nationwide, the surge in sales culminates a year in which the FBI ran 16.8 million background checks for gun buyers, the most ever. Sales skyrocketed the Friday following the November 6 election, breaking all-time records and crashing the FBI's NICS background check system. Now, following the shooting of 20 school children and 6 adults, gun sales of all types are again spiking.Mike Olden, owner of Mr. O's, said it's difficult to get through to NICS to do background checks. “All circuits are busy; the buying is so rampant right now that it's escalating to crazy,” he states. “It's been that way since Monday. You get a recording telling us to call back later.”Olden attributes the increase in sales to the response by political and media figures to pass legislation to restrict possession of certain categories of firearms. But, long term, Olden doesn't believe gun control, including banning specific types of guns, is the solution. Besides being a strong proponent of the Second Amendment, he has a more practical reason. “You can't just ban them; the guns will still be out there. We need to grandfather past purchases or the government will have to buy them back,” Olden stated. “With our financial situation, we can't afford to buy them back.”At Wright's Enterprises, gun sales are booming according to Cecile Coulombe, who noted that they had sold four assault rifles in two hours. Coulombe agreed that calling NICS for background checks was taking a long time to get through.The definition of an assault rifle is disputable but the general consensus is it is fully automatic or has burst capability. It has an intermediate cartridge and a detachable magazine. The rifle used in the Connecticut attack, the AR-15, was also used in the shooting of 12 people in a Colorado movie theater this past summer. The AR-15 is considered a semi-automatic rifle, which was originally developed for the United States armed forces as the M16. Later purchased by Colt, it was marketed as a semi-automatic version of the same design. The hammer and trigger design are different to comply with the Alcohol,Tobacco, Firearms and Explosives (ATF) requirement that civilian weapons not be easily converted to full-automatic.The ban on assault weapons was instituted in 1994 and expired in 2004, after which modifications to upgrade semi-automatic weapons to fully automatic became legal despite some federal restrictions. The AR-15 is easily convertible to automatic.