During flashbacks of Saya's past in Vietnam, US soliders are carrying M16A1 Assault Rifles. The soldiers fire these weapons at Saya when she is going berserk, but the rounds do little to slow her down.
Saya's father George owns a M1911 which is seen drawn during flashbacks scenes with him and Saya. George mentions that he is ex-US military, so it's likely he kept this weapon after leaving the military.
Kai later takes this weapon to chase down the Chiropteran that attacked and wounded George.
After Saya's first Chiropteran encounter, a U.S. Special Forces team armed with Colt Model 933 carbines, secures the area. Later, Lewis is seen weilding a Model 933 when Kai approaches him on his motorcycle. In both instances they are fitted with Surefire M900 weaponlight foregrips and EOTech red dot sights.
When Saya, Hagi and David go to rescue George, David equips himself with what appears to be a Franchi SPAS-12 with a removed stock and loaded with slug rounds. Lewis mentions that this weapon is not enough to kill a Chiropteran, but David comments that it's all he needs because Saya is the ultimate weapon against Chiropterans.
