SA80's are used by the British Army team during the training exercise at the start of the film, with military blank adapters and SUSAT sights attached. They are later ditched when the team discover the dead Special Ops team, as they would be useless against a real threat.
Browning Hi-Power
The Browning Hi-Power is used many times throughout the film, first by Captain Ryan (Liam Cunningham) during Private Coopers (Kevin McKidd) Special Ops training, then by Sgt. Wells (Sean Pertwee) during the attack on the farmhouse, and finally by Pvt. Cooper to kill Ryan in his werewolf form.
On an interesting note, during Cooper's training, Ryan's Browning doesn't have a magazine in the gun yet he manages to chamber a round then shoot a dog in the head and not have the slide lock back.
If there's no mag in the gun, then of course the slide won't lock back. The magazine has to be in the gun for that to happen. -MT2008
Heckler & Koch MP5A2
The Heckler & Koch MP5A2 is first seen during Pvt Coopers Special Ops training and are later taken from the dead Special Ops camp.
H&K SR9(T)
A Heckler & Koch SR9(T) with the scope removed and a 20-round magazine is used by Private "Spoon" Witherspoon (Darren Morfitt) and then by Private. Terry Milburn (Leslie Simpson) after swapping his MP5A2 for it. After Terry is taken and killed by the werewolves this weapon is not seen again throughout the rest of the film, although he was not shown holding it when taken. The rifle used in the movie had difficulty handling blanks and the bolt had to be manually cycled occasionally. The reason for the scope removed and the 20 round magazine is most likely because the SR9 is supposed to be a stand in for a H&k G3A3.
Can anyone explain to me how this gun is an SR9(T)? It looks to me like a regular G3A3 with its flash hider removed. -MT2008
Mossberg 500
A Mossberg 500 shotgun is taken from the Special Ops camp and is used by Pvt. Joe Kirkley (Chris Robson) throughout the farmhouse attack.