The following weapons were seen in the movie Papillon:
Fusil Berthier Modèle 1907-15 Rifle
Berthier Model 1907-15 rifles are used by French Soldiers and Penal Colony guards as well as Papillon (Steve McQueen), Dega (Dustin Hoffman) and Maturette (Robert Deman). During the First World War Berthier rifles were chosen to colonial troops, instead of the Lebel 1886 (rifles erroneously credited before on this page), so the film is historically correct as it is set in 1930.
Erma EMP-35 submachine gun
The Gendarmes are armed with the Erma EMP-35 submachine gun when escorting the prisoners through the streets at the start of the movie. In real life, EMP-35 submachine guns were issued to the French Police.
12 Gauge Double Barrel Shotgun
Colt Official Police
What appears to be a Colt Official Police revolver is pulled by the South American Police on the beach when confronting Papillon and Dega.