During the introductory sequence, the fictional F/A-37 "Talon" fighter piloted by Lieutenant Kara Wade (Jessica Biel) is fired on by antiaircraft guns, including a Bofors 40mm gun in a single mount.
M61 Vulcan
M61 Vulcan cannons are presumably mounted on the various US fighters seen during the movie, but are also seen clearly; several appear in the introduction in M167 Vulcan Air Defence System (VADS) towed mountings, while others are visible in Phalanx installations on the US carrier, nominally USS Abraham Lincoln. See trivia below.
Beretta 92FS
The Beretta 92FS is the standard sidearm of US military personnel, standing in for the military M9.
Calico M-960A Submachine Gun
A Calico M960A Submachine Gun is carried by the bodyguards of a group of terrorists heading for a summit in an abandoned building in Rangoon.
Norinco Type 56
The Chinese AK/AKM variant, the Type 56 (and 56-1 the folding stock version) are the most commonly seen AK47/AKM rifle in movies and television (at least those done by U.S. Production companies). The Type 56 (full stock) version is commonly seen in the movie, usually in the hands of terrorists of many different stripes. Terrorist guards from several organizations are seen wielding the weapon in Rangoon, Islamic Extremists in a mountain fortress in Tajikistan, and North Korean Soldiers.
AK-47
In addition to the many Norinco Type 56 Chinese AK rifles, terrorists are also seen wielding what looks like original milled receiver AK-47 rifles with original front sights (not the hooded Type 56 sights). However, being how 'new' they look, they can be the third pattern AK-47 "Legend Series" rifles imported by Poly Technologies, Inc, between 1988-1989. Those were high end identical clones of the original AK-47 rifles but very few were imported.
Norinco Type 56 Target
Tajikistan terrorists are seen using a long barreled Type 56 variant rifle. It has an underfolding stock and a long barrel but no bipod.
SA Vz. 58
The SA Vz.58 assault rifle is carried by Tajikistan terrorists at the mountain fortress.
SKS Rifle
Carried by Tajikistan terrorists, they appear to be the Russian built SKS rifles with laminated stocks and full blade bayonets.
Heckler & Koch PDW (MP7 prototype)
A prototype Heckler & Koch MP7, the Heckler & Koch PDW, is carried and used by Lieutenant Kara Wade (Jessica Biel) when she is shot down over North Korean Territory. Visible differences between the prototype and final version include the arrangement of the three vent holes in the handguard (a straight line rather than a "V" shape) and a half-length rather than full-length top rail.
Colt Model 733
Though the official Colt 733 was 11.5" we see 10" M16 short carbines, in the hands of covert ops thugs in Alaska.
At the mountain fortress, there are several gunners who are manning World War Two vintage Oerlikon 20mm Cannons.
SA-7 Launcher
SA-7 Grail surface to air missiles are fired at EDI and the other aircraft as they attack the mountain fortress.
SVD Dragunov
A North Korean marksman with the group tasked with tracking down one of the pilots hands an SVD Dragunov sniper rifle to his superior, who uses it for the rest of the movie.
Zastava M70AB2
A curious thing is that all the North Korean Troops carry the Yugo Zastava M70AB2 AK rifle (with a flashlight taped to the front hand guard).
Heckler & Koch G36K
Lieutenant Ben Gannon (Josh Lucas) takes a Heckler & Koch G36K fitted with a Heckler & Koch AG36 Grenade Launcher and a Bundeswehr ZF 3x4° dual optical sight from a Black Ops guard and uses it against them in the hangar. Black Ops thugs can also be seen using G36K rifles with Bundeswehr-standard sights.
Heckler & Koch AG36
Mounted under Lieutenant Ben Gannon (Josh Lucas)'s Heckler & Koch G36K is a Heckler & Koch AG36 Grenade Launcher. This is one of the earliest appearances of this grenade launcher in a film. It is only fired once during the movie; for some reason, a sound like a shotgun's pump being operated is foleyed in as Gannon prepares to do so, despite that he is simply pointing the weapon rather than loading it.
Austeyr F88
A F88 Austeyr is held by a Black Ops guard, Gannon tell him to set it on the ground. When Gannon is ambushed, the guard picks it up again, but is shot by Gannon. Austeyr F88 rifles can also be seen in the Alaska Base Armory.
Austeyr F88S
One of the Black Ops thugs who surround the hangar is carrying an Australian Austeyr F88S.
Colt M4 Carbine
An M4 Carbine is used by a guard to ambush Gannon. Also M4s are seen in the Alaska Base armory against the wall and being handed out to guys sent to kill Gannon.
M60 Machine Gun
An M60 machine gun is seen on the table of the Alaska Base Armory
Leader Dynamics T2 MK5
Leader Dynamics T2 MK5 assault rifles are seen in the Alaska Base Armory and being handed out to guys sent to kill Gannon.
L1A1 Self Loading Rifle
In the Alaska Base Armory, we also see Australian Wood stocked L1A1 SLRs against the wall and also being handed out.
Near the end of the movie Captain George Cummings (Sam Shepard) draws a Walther P99 from his washbag.
Trivia: Carriers
While the carrier in Stealth is nominally the USS Abraham Lincoln, there are actually three carriers in the movie; as well as the correct one, USS Nimitz and USS Carl Vinson are shown at various times during the movie.