The Omega Man is a 1971 science fiction thriller based on the novel "I Am Legend" by Richard Matheson. In this film version, Charlton Heston plays Col. Robert Neville, who unexpectedly becomes the last human on earth devastated by a deadly virus. The novel was previously adapted as the 1964 film The Last Man on Earth and was adapted again for the screen in 2007's I Am Legend.
The following firearms were used in the movie The Omega Man:
Charlton Heston as Neville uses a Browning Automatic Rifle aka BAR M1918 Variant (with M3 infrared starlight scope and bipod removed) in The Omega Man. The mutated plague-victims in "The Family" believe that Science and Technology are what ultimately led to the germ warfare that destroyed human civilization, so they categorically don't believe in using any technology above the bow and arrow level, particularly guns. Neville, meanwhile, has no compunction against using technology, i.e. hunting The Family with automatic rifles fitted with infrared scopes so he can see at night as well as they can.
Robert Neville (Charlton Heston) has a German MP40 in his gun rack at his penthouse. It is amongst the guns smashed to the ground by Mathias' followers, but Neville manages to grab it and kill several mutants. A pivotal event in the film is when Neville has a chance to kill Mathias, but his gun jams (possibly a shell separation in the chamber or dud ammunition, since the open bolt mechanism works fine).
Thompson M1A1
There is one scene that an M1A1 Thompson Submachine Gun can be seen strapped to the back of Dutch's (Paul Koslo) motorcycle seat. Also an M1A1 is seen on Neville's Gun rack in his apartment.
M3 Carbine
Apparently the gun that the IR scope was taken from, there is an M3 Carbine sans scope (with the fore grip and electrical wiring attached) sitting on one of Neville's chairs in the apartment near the window. The M3 Carbine is also later seen in the gun rack.
Handguns
Colt 1903/1908 Hammerless
The first time that Neville meets Lisa (Rosalind Cash) she is pointing a Nickel plated Colt 1903/08 Hammerless Pistol with Pearl grips at him. Unknown if it is the 32 or 380 caliber model. Note: In the very first scenes, Lisa's pistol is a silver painted rubber gun, probably the stunt weapon she handled during the night filming and the subsequent motorcycle chase.
M1911A1
Robert Neville (Charlton Heston) carries a M1911A1 in a brown holster throughout the film. He never draws nor fires it, but several M1911A1s are visible on a gun rack in Neville's Apartment.
Dutch (Paul Koslo) carries a nickel plated Single Action Army Revolver with ivory grips. This is most noticeable during the night time rescue of Neville at Dodger Stadium and later when Dutch rides up in his Motorcycle at the sanctuary.
Colt Official Police
A Colt Official Police (.38 Special) is incidentally seen on the seat of an LAPD patrol car, the officers dead from the plague.
Completely incidental and briefly seen, a dead Los Angeles Police officer lies near his Ithaca Model 37 pump shotgun, a victim of the plague It is hard to see since the shot is a fast zoom to the dead man's face. Trivia: The actor playing the dead L.A. cop can be seen breathing when the camera lingers on him.
Robert Neville's Gun Racks
A variety of weapons that are not seen or utilized anywhere else in the film are seen here.
Madsen M50
Several Danish Madsen M50 Submachine guns are seen in Neville's Gun rack in his apartment.
Luger P08
Never fired nor carried in the film, there is a Luger P08 Pistol on a gun rack in Neville's Apartment.
M1 Carbine
A post war M1 Carbine is visible on one of Neville's Gun racks.
High Standard Shotgun
A High Standard shotgun (not sure of model) is visible on one of Neville's gun racks, but it is never fired or used.
Several rifles which appear to be M1903 variants are on the rack but never fired or handled. One of them is briefly seen with a scope. Hard to see if it is an 03-A3 or an O3A4, but the scope is a commercial one.
Trivia Special
Early Flashlight mounts
As in other films before the advent of integral flashlight mounts for submachine guns and other firearms, shooters had to make do. The DIY crude metal clamps that Robert Neville (Charlton Heston) uses to affix a large and bulky flashlight to his M76 Submachine gun was the precursor to the Surefire (and others) tactical lighting systems we enjoy today.