Most of the small weapons used during the shooting scene did not exist at that time, the movie is settled e. g. a Colt 38 Special Police Service weapon (on markets after the turn of the century) several Magnum Type revolvers (S & W .357 Magnum) which did not exist before the 1960ies. Very special are Guererros revolvers, which were simply fantasy weapons: a three barrel Colt Dragoon front, mounted on a Le Mat rear end with the Le Mat 9 shoot cylinder.
During firefights, the weapons of most oft the characters are changing between the cuts: As example: Guererro starts the fight with his special fantasy revolvers, in the next scene he holds two modern Magnum revolvers (either S & W or Colts). This happens in almost any shooting scene.
When Calathea shoots at Red on the street, she is shown from behind, firing one shot from a double-barreled shotgun. One second later, she is shown frontally, holding a winchester rifle and repeating it for another shot at Red.
What are the differences between the R-Rated and Unrated Version?
A
US audiences get the film in two different cuts. The "R"-rated version omits two graphic moments of violence and avoids female nudity by using appropriate alternate material. Since the DVD and Blu-ray have the Unrated on board, as well, that shouldn't bother too many viewers. A detailed comparison between both versions with pictures can be found here.