It's been reported that the bullets are .223 calibre but, as maany guns can fire different calibrations after modifications, the rifle is still unknown. Many guess it to be a Remington 700.
According to CNN the bullets from the Bushmaster (which is the civilian version of the military M-16) match those used in "all but 3" of the 14 shootings. No mention of what was used in the others, although he also had an AR-15 assault rifle.
According to CNN the bullets from the Bushmaster (the civilian version of the US military M-16) matched those from "all but 3" of the 14 shootings. No mention of what was used in the other 3, but they also found an AR-15 assault rifle at the guy's house.