The Remington 870 is used by the State police, specifically during the Highway chase.
M16 SP1
A State trooper riding in a Helicopter fires on Jim Halsey during the Highway chase with a M16/SP1. Several of the State troopers escorting John Ryder (Rutger Hauer) are also armed with M16/SP1s.
Custom Smith & Wesson 629
At the end of the movie, Jim Halsey (C. Thomas Howell) grabs Captain Esteridge's sidearm. It is a 2.5"-barreled, Mag-na-ported S&W N-frame (probably, a Smith & Wesson 629 ). A similar gun can be seen in the movie Extreme Prejudice. A continuity error is seen when John Ryder jumps through the windshield, Jim Halseys 629 turns into a Smith & Wesson Model 66.
Franchi SPAS 12
A Franchi SPAS-12 is carried by the State police escorting John Ryder to the state prison. Both John Ryder and Jim Halsey use the Franchi SPAS-12 at the climax of the film.]]
Trivia
In addition to scenes shot in the studio, filming locations include Amboy, California, Barstow, California, Death Valley National Park in California, Imperial County, California and Lake Mead in Nevada.