Doomsday was a 2008 sci fi action film, written and directed by Neil Marshall, who wrote and directed the previous film Dog Soldiers. As is done with many British Filmmakers, he uses actors from his earlier movie to star in his current one. In fact nearly the entire cast of Marshall's film Dog Soldiers appear in this movie.
Richter's assistant, Afro Girl (yes, that is her name in the credits) (Eloise Cupido) wields a nickel plated Colt Single Action Army.
Walther P38
Major Eden Sinclair (Rhona Mitra) uses a custom suppressed Walther P38 as her main handgun during the capture of the slaver's ship. Later the same handgun is used by Sol during the highway chase scene.
Smith & Wesson Model 6
Bill Nelson (Bob Hoskins) uses a S&W Model 64 (the stainless steel version of the Model 10) to try and save Prime Minister John Hatcher (Alexander Siddig) from a rampaging infected man.
Webley Mk VI
Prime Minister John Hatcher (Alexander Siddig) uses a .455 Webley Mk VI to commit suicide after being infected with the virus.
Vektor CP1
DDS soldiers are shown using a modified version of the Vektor CP1 pistol. Their version has an extended ported barrel and a module under the barrel which holds both a light and laser. The laser turns on when the trigger is depressed, but this is most clearly seen when Eden Sinclair uses it during daylight.
Unknown Pistols
Used by a thug at the seaport and later by guards at the Government Headquarters.
Submachineguns
Armscor BXP
A guard, during the assault on the slaver ship, carries a Armscor BXP submachine gun. This weapon was selected due to the scene being filmed in South Africa and being readily available to South African Armorers. The weapon is only briefly seen.
Rifles
L85A1 Assault Rifles
The L85A1 assault rifles are used by British soldiers during the initial outbreak of the Reaper Virus (circa 2010) which would almost correct (they would have the upgraded L85A2s). Upon close inspection, the rifles do seem to be Umarex Airsoft rifles with the flashes, bolt movement and flying brass casings digitally inserted later, but they did a good job on many of the scenes. What is odd is that the L85A1 rifles have the tiny Union Jack Flag sticker on them, which as far as I know, only appears on the toy guns.
Vektor CR-21
Most of the DDS agents carry Vektor CR-21 assault rifles equipped with flashlights, laser sights, and sound suppressors. In the early part of the film, DDS agents carry CR-21 rifles with the original South African optical sight. During the mission in the badlands, the DDS Soldiers carry CR-21 that have SUSAT optical sights mounted.
Heckler & Koch G36K
Soldiers at the government Headquarters in London are seen with G36K rifles.
Customized L42A1 Sniper Rifle
A British sniper stationed on the wall snipes an infected man with an L42A1 bolt action sniper rifle in a thumbhole sniper stock with a Parker Hale Bipod and elevated sniper cheek rest - 7.62x51mm.
South African Vektor R4
One of the guards of the slaver ship that's docked in the harbor carries a Vektor R4 with stock folded.
Shotguns
Neostead Shotgun
A Neostead shotgun is used by Chandler (Rick Warren) and then Eden Sinclair (Rhona Mitra) during the sweep of the abandoned hospital. The shotgun is used to blast a hole in the elevator ceiling and cut the cable. In the DVD extras, the director Neil Marshall claims that this is the only movie so far that has featured this unusual South African Pump Shotgun.
Armsel Striker
Miller (Chris Robson) uses a Rotary drum shotgun like the Armsel Striker during the crashed APC scene. What makes this scene confusing is that the shotgun used really looks like a low end Cobray Streetsweeper and not the higher end Armsel Striker. Since this scene was filmed in South Africa one would expect the armorers to favor the better made Armsel Striker shotgun. One theory is it is an older version of the Striker which had a key style that was eventually copied by SWD/Cobray for the Streetsweeper, but as far as the film goes, the shotgun more closely resembles what we now know to be the StreetSweeper and not the Striker, despite all the facts pointing towards the Striker.
Sawed Off O/U Shotgun
Richter (Jeremy Crutchley), the trafficker in Scottish slave labor, uses a sawed off Over/Under double barreled shotgun to kill his business associates (whom he thinks betrayed him) and to hold a DDS Agent John Michaelson (Tom Fairfoot) hostage - 12 gauge.
South African Musler 12 gauge tactical Action
A blonde woman, bathing in the cast-iron tub aboard the ship, uses a Musler 12 gauge shotgun with extended magazine tube and pistol grip. Note: Either this is a special left handed eject model or the entire sequence has been 'flipped' in post. This shotgun normally has an ejection port on the right side just like a Mossberg 500 (upon which the shotgun is based), so this footage must be reversed, since the gun is not like the Ithaca 37 which has no side ejection port.
Heavy Weapons
Vektor SS-77 Machine Gun
Instead of the British Army issued L7A2, the trooper on the top of the armored vehicle is using a Vektor SS-77 GPMG. This is because the sequence in question was filmed in South Africa so armorers used what was at hand.
Twin Barreled Sentry Guns
The British army in the story, abandons manning the wall about five years after the northern lands were sealed off and have been using Motion sensor activated Sentry Guns to destroy anything that moves. Sgt. Norton mentions that the guns only wreak havoc on the 'local wildlife' since they haven't had a human target for twenty years, just as the guns focus on and destroy a rabbit. The guns themselves are just fabricated props and not based on any real world firearm or auto cannon.
Vektor MG-4
During the hospital scene, the DDS troops pass a Vektor MG-4 version of the Browning M1919 machine gun. It's mounted on what looks to be an anti-aircraft tripod and the debris of twenty five years of neglect.
British soldiers fire CS gas and smoke grenades at the crowd from atop the quarantine wall. Though difficult to clearly see, they are single shot launchers with twin pistol grips, strongly resembling the Defense Technologies 1315 37mm launcher.
Fragmentation Grenade
A fabricated Prop Sci Fi Fragmentation Grenade is used when Carpenter releases on inside the APC after his throat has been slashed by a savage starved girl.
High Explosive Grenade
Bandoleers of these long silver fabricated HE grenades are seen on the armory table and also carried by Sgt. Norton throughout the film. They are most prominent during the castle escape when Norton retrieves his bandoleer from the castle armory and starts blowing things up. The grenades are fabricated Sci Fi Props.
Silicon Foam Grenade
Sci fi prop "Silicon Foam" grenades are used during the escape from the hospital to enable the DDS soldiers to survive an elevator drop by encasing them in foam. Miller (Chris Robson) refers to them as "Silicon Foam Grenades" during the initial meeting with Major Eden Sinclair.
Bow & Arrow
Normally antique weapons (like bows and arrows) are avoided in that there is no way to identify the make, model or history of the weapon used in a film, however, they are sometimes listed when used by major characters, to track how many times they appear in gun heavy films. In films like Geronimo or Braveheart there is no need to list the bows and arrows since they are expected weapons, however, listing their usage in modern or sci fi movies is an interesting statistic though they do not merit their own weapons page.
Crossbow
Again, the usage of crossbows as high profile weapons in films that are not period pieces and has modern firearms prominently used is noteworthy.