Escape from New York

The weapons seen in this movie are:

M16A1

The US Police Force Soldiers throughout the film use M16A1 Rifles with their handguards removed in order to make them look more futuristic. The President (Donald Pleasence) is seen using one taken from a dead guard to kill the Duke of New York (Isaac Hayes).

Smith & Wesson Model 36

Bob Hauk (Lee Van Cleef) is seen checking a nickel-plated Smith & Wesson Model 36 before his meeting with Snake (Kurt Russell).

Smith & Wesson Model 67

Snake's sidearm in the film is a Smith & Wesson Model 67 with a scope mounted on it. During the climax, Maggie (Adrianne Barbeau) fires it at the Duke before she is run down by him. You can tell it's a Model 67 because it has adjustable sights but lacks the lug that protects the ejector rod on the Model 66. Therefore it's a 38 Special revolver and not a .357 magnum.

MAC-10

The other weapon the USPF issues to Snake is a MAC-10 fitted with a sound suppressor and a scope mounted on the silencer. After Snake is captured, the Duke of New York uses it for the remainder of the film, notably using it to shoot at, but not kill the President.

Various Crossbows

Various Crossbows are seen weilded by numerous Thugs.