A large quantity of unused ammunition was recovered from the school along with three semi-automatic firearms found with Adam Lanza: a .223-caliber Bushmaster XM-15 rifle,[61] a 10mm Glock 20 SF handgun [5][62] and a 9mm SIG Sauer handgun.[4][63] A shotgun was found in the car Lanza had driven to the school.

http://en.wikipedia.org/wiki/Sandy_Hook_Elementary_School_shooting