The SIG-Sauer P226 is the preferred sidearm of Red Troop and is used throughout the series. It is frequently seen holstered whenever the team are wearing their counter terrorist gear, but is normally only used for undercover work.
A Browning Hi-Power was prominently used by Henno (Ross Kemp) in "Changing of the Guard" (Episode 4.1). Patrick (Sam Callis) can also briefly be seen with a Browning during a mock terrorist assault in "Slow Bomb" (Episode 4.5).
A nickel plated Desert Eagle of some sort can be seen being carried by one of the gang members in "Violent Solutions" (Episode 4.4). It is never shown clearly, so the particular model cannot be identified.
Glock 17s can be seen in several episodes, as the standard pistol carried by armed British police. In this season, most of the Glock 17s are 3rd Generation models.
The standard-issue weapons for the SAS unit Red Troop in the TV show are Heckler & Koch MP5A3 submachine guns, which are always seen with Surefire fore ends and tactical flashlights as well as the SEF-style lower receiver. These weapons are typically used in Red Troop's domestic hostage rescue missions.
The other SAS unit, Blue Troop, also use identical weapons, as do many Metropolitan Police SO19 (now CO19) officers throughout the show.
A Heckler & Koch MP5KA1 is used by Slava (Daniel Betts) in "Changing of the Guard" (Episode 4.1). The MP5KA1 is a version of the original MP5K designed for concealed carry (it lacks the H&K diopter sights in order to avoid getting snagged on clothing when being drawn quickly from beneath a jacket).
Several of the Al-Qaeda terrorists in "The Dividing Line" (Episode 4.3) carry rifle resembling AK-74s. The rifles have the flash hiders and furniture of AK-74s but appear to be chambered in 7.62x39mm, indicating that they are mock ups, most likely based on AKMs.
CAR-15s are used commonly by the SAS in the show, almost always fitted with a Cobray CM203 grenade launcher. The "Stowaway" pistol grip and the areas of black tape covering logos on the lower receiver suggest that this weapon is built from an Olympic Arms rifle, most likely a K3B.
Throughout season 4, Red troop use the M4A1 Carbine as their standard weapon. It is possibly not actually a Colt manufactured M4, as when fitted with the standard handguards it does not have the M4 style double heat-shield handguard and instead has the slimmer single heat-shield handguard found on earlier Colt carbines. It is seen in all episodes and can be seen with a large number of accessories, including Aimpoint Mark III scopes, Aimpoint 5000 scopes, Cobray CM203 37mm flare launchers, M203 40mm grenade launchers, suppressors, RIS handguards, gooseneck rails and PRR pressel switches. All members of the team carry M4s except for Louis, who carries a mocked up CAR-15 with a CM203.
FEG NGM-81s can briefly be seen in "Charlie Bravo" (Episode 4.2) and "Dividing Line" (Episode 4.3), It can be identified by its PKM flash hider and the combination of an AK-47 gas block but a straighter magazine.
An FN FAL with a metal foreend and fitted with a telescopic sight is used by one of the Colombian soldiers in "Charlie Bravo" (Episode 4.2). It lacks a flash hider.
A Heckler & Koch G36 variant can be seen in the CNC (Civil Nuclear Constabulary) armoury in "Slow Bomb" (Episode 4.5). The handguard and barrel is never seen so it is not possible to confirm the exact variant, but it most likely a Heckler & Koch G36C as it is fitted with a G36C type carry handle, a G36C has previously be seen on the show, and G36Cs are used by the real CNC.
One of the British police snipers in "Violent Solutions" (Episode 4.4) can be seen with a Heckler & Koch HK33 fitted with a bi-pod and telescopic sight.
Regular British forces throughout the show are seen wielding L85A1 service rifles. They are never operationally carried by Red Troop, like their real life SAS counterparts, however they are used for ceremonial purposes. Since Ultimate Force was filmed after 2000 the use of L85A1s is anachronistic, having been replaced by the L85A2 variant by Heckler & Koch.
Two of the gangsters in "Violent Solutions" (Episode 4.4) carry modernized Valmet M62s. Both of these weapons are fully chrome plated (including the magazine). One of the rifles does not have the standard iron sights of either an M62 or M76, and instead of the sights being located at the rear of the dust cover they are nearer the front and appear to be of a simpler design (a similar rifle can be seen in "Something to Do with Justice" (Episode 1.6) without the chrome plating).
Corporal Finn Younger (Jamie Michie) acts as Red Troop's sniper in Season 4, and can often be seen with an Accuracy International Arctic Warfare, with the phrase "WHO-HIT-JOHN?" engraved on the right side of the butt. The rifle is erroneously identified as an "L97 with the long barrel", which is not a real variant. This was likely a reference to the L96A1 which is the British Army designation for the Precision Marksman variant, however as this rifle is the Arctic Warfare the correct designation would be the L118A1.
One of the US special forces soldiers in "Dividing line" (Episode 4.3) can be seen using an unknown Heckler & Koch G3 based sniper rifle. The rifle which it most resembles is an Heckler & Koch G3SG/1 , however it has several differences: the rifle has a conventional trigger pack (lacks the secondary setting trigger), a larger E&L cheek riser, an E&L adjustable stock extension, no iron sights and what appears to be a thicker and longer barrel without a flash hider. Due to the rarity of G3SG/1s, it is more likely that this rifle is a regular G3A3 which has had a number of modifications and after-market parts added. The same rifle can also be seen on the Season 3 page where the same rifle is used by an SO19 sniper.
Dave (Louis Decosta Johnson) carries a FN Para Minimi in "Charlie Bravo" (Episode 4.2), feeding from STANAG magazine as opposed to belted ammunition. A Para Minimi is also used by one of the American special forces soldiers in "Dividing Line" (Episode 4.3) where it uses the more common belt feed.
A Browning M2HB can be seen in "Charlie Bravo" (Episode 4.2) being used by rebel soldiers. The M2HB is later relocated by Louis (Christopher Fox) and Finn (Jamie Michie), and Henno (Ross Kemp) instructs several Columbian soldiers in its use.
A KPVT can be seen mounted in the turret of a BRDM-2 in "Changing of the Guard" (Episode 4.1). Note the slot next to the KPVT on the turret, which should hold a PKT which is absent.
An M60 machine gun can be prominently seen in "Dividing Line" (Episode 4.3) where is is used by one of the American special forces soldiers. An M60 can also briefly be seen being carried by one of the Columbian soldiers in "Charlie Bravo" (Episode 4.2).
Finn (Jamie Michie) uses an MG42 in "Charlie Bravo" (Episode 4.2) whilst instructing a group of Columbian soldiers. An MG42 is also used by AUC fighters and can be seen during the attack on their base.
A chrome plated Mossberg 500 Cruiser with a sight mount fitted and the barrel cut down to the magazine tube is used by one of the gangsters in "Violent Solutions" (Episode 4.4). A full length Mossberg 500 Cruiser is used by another gangster fitted with a vertical foregrip.
In "Violent Solutions" (Episode 4.4) the gang leader Monty (Robbie Gee) can briefly be seen with a Remington 870 Police Folder with the stock removed. Louis (Christopher Fox) carries a Police Folder with the stock in "Slow Bomb" (Episode 4.5) but it is never used.
Several of the American special forces soldiers in "The Dividing Line" have M203 40mm grenade launchers mounted under their M4s, rather than the Cobray CM203 37mm flare launchers used by Red Troop as M203 stand-ins.
A number of LAW 80s can be seen in "Violent Solutions" (Episode 4.4). These weapons are the inert training version of the weapon, which appear to have had the middle section painted black, most likely to cover up the yellow "DRILL" lettering that would otherwise be visible.