The film opens with a Columbian soldier in a personel truck seen armed with an SKS rifle in the Columbia shootout.
G3
A soldier is seen briefly with a G3 rifle, or what could be an HK91 rifle, but it is never seen close enough.
Steyr AUG
A Columbian soldier is seen very briefly with a Steyr AUG assault rifle.
Browning M2 M1919A4 .30 cal
Seen briefly mounted on a Columbian jeep.
RPD
A Columbian soldier is seen briefly using an RPD.
FN FNC
A Columbian soldier is seen briefly with and FN FNC carbine.
M16A1
Columbian soldiers can be seen with M16A1 rifles.
Colt Python
Campus guards and police officers, as well as the border patrol men all use Colt Python .357 revolvers.
Beretta 92SB
Jack Thorpe, the American terrorist uses a Beretta 92SB as his sidearm. When first at the school, he shows it to the guard. When the guard goes for his gun, it switches to a little .22 auto soundsuppressed mockup. A police infiltrator uses a Beretta 92SB at the end of the film to deliver the fatal shot to Luis.
Glock 19
Luis Cali (Andrew Divoff) uses a Glock 19 2nd generaion compact 9mm as his weapon of choice.
Norinco Type 56-1
One of the terrorists uses a Norinco Type 56-1, as noted by its hooded front sight and under-folding stock. It is fitted with an AKM style muzzle break, making it similair to the gun Danny Trejo used in Heat, meaning it was a semi-auto chinese import, converted to full-auto fire for the film and fitted with the slanted muzzle by the guns importer.
Poly Tech Legend AKS-47
The terrorist who commonly partners up with the other man with the 56-1 uses what appears to be a Poly Tech Legend AKS-47, a model most closely resembling a genuine AKS-47.
Browning M2 M1921
The belltower guards set up a .50 caliber Browning M2 machine gun to watch the front gate.
M72 LAW
The belltower guards use an M72 LAW 66mm anti-tank launcher to blow up the police car. Thorpe tries to use one on the infiltration helicopters, but is shot to pieces by the choppers guns.
MP5K
The terrorists overrunning the school are armed mainly with MP5K submachine guns. Army Infiltration members use them as well. Billy Tepper (Sean Astin) steals one from a terrorist when the Army infiltrates the school.
Uzi Carbine
One of the terrorists is seen multiple times using an Uzi Carbine, the civilian version of the Uzi, fitted with a 16in barrel with a barrel shroud. It seems the armorers converted it to full-auto fire for the film. It is most obviously used when Joey Trotta (Will Wheaton) knocks out a terrorist and attempts to kill another with the the Uzi, failing as the muzzle rise, very innaccurately depicted, raises his fire to the sky, and he is gunned down by the terrorist's MP5K.
Mini-14
Thorpe uses an Mini-14 with a synthetic stock and scope to kill the border patrol men.