Desperado is the 1995 sequel to the 1992 action film El Mariachi. The film was also directed by Robert Rodriguez and stars Antonio Banderas as the gun for hire known as the "Mariachi", who keeps his firepower hidden in his guitar case. Rodriguez and Banderas would complete the Mariachi trilogy with 2003's Once Upon a Time in Mexico.
The following weapons were used in the film Desperado:
El Mariachi (Antonio Banderas) packs matching Ruger KP90s as his main weapons in the film. Tavo (Tito Larriva) fires a Ruger KP90 at El Mariachi (Antonio Banderas) as he flees the shootout at the Tarasco bar. It's likely that it's one of Banderas' KP90s simply being reused in a different scene. The Ruger KP90 is also the pistol Tavo (Tito Larriva) uses to put a bullet through The Pick Up Guy's (Quentin Tarantino) head.
The pony-tailed ganster uses a Beretta 92FS Inox pistol with Ivory grips to hold up El Mariachi in the bar. Some random thugs can be seen using them as well.
El Mariachi (Antonio Banderas) carries a scoped Wildey Magnum pistol in his guitar case. One of Bucho's hitmen is also seen carrying a Wildey Magnum in the film.
Empty Gun Man (Diego Sandoval) brings a suppressed Taurus PT99 to the Tarasco bar shootout. El Mariachi is later seen with the same PT92 in his guitar case later, although it lacks the suppressor. It is noted as a Taurus PT99 based on its frame mounted safety and raised adjustable sights.
Tavo (Tito Larriva) fires a black Desert Eagle Mark XIX in .50 AE (determined by bore diameter) at El Mariachi (Antonio Banderas) as he flees the shootout at the Tarasco bar. Bucho (Joaquim de Almeida) also begins to kill his own men with the same black Desert Eagle. El Mariachi (Antonio Banderas) later kills one of Bucho's henchmen on the roof of Carolina's (Salma Hayek) bookstore who is holding the same black Desert Eagle.
While the Desert Eagle had appeared in many action movies by this time, Desperado appears to the very first film ever to feature the latest Mark XIX variant in .50 AE (which was brand-new in 1995).
Bucho (Joaquim de Almeida) seems to have a taste for exotic pistols, the Beretta 93R he carries is a very rare version of Beretta's popular 92 model capable of 3-round burst fire. Bucho's (Joaquim de Almeida) Beretta 93R is taken by Zamira (Angel Aviles) who makes use of its burst fire capability in the attack on Navajas (Danny Trejo). The Beretta 93R is later reused by one of Bucho's henchmen who fires at El Mariachi as he jumps from the roof of Carolina's (Salma Hayek) book store.
Although never seen fired, the Codpiece Revolver is one of the few firearms in the film with dialogue devoted to it. A similar codpiece revolver was later used in Robert Rodriguez's film From Dusk Till Dawn, although it was a slightly more complex piece able to fold away when not in use. Originally a scene was shot where El Mariachi used the codpiece, which was hidden under his pants, to shoot Ponytail thug, before whipping out his Ruger P90s and finishing him.
The Tarasco bartender (Cheech Marin) uses a suppressed Smith & Wesson Model 19 revolver. In reality, very few revolvers can be sound suppressed because of the gap between the cylinder and barrel. The 1895 Russian Nagant revolver is one of the rare revolvers that can be sound suppressed. Upon firing, the cylinder moves forward and seal with the barrel, leaving no gap. You can see it here.
El Mariachi (Antonio Banderas) can also be seen using a Rossi Overland Sawed Off Double Barreled Shotgun as one of his main weapons in the film and can be seen firing up to six rounds from two barrels thanks to movie magic. It was built and supplied by Stembridge Gun Rentals.
In the shootout at the Oro verde bar in Saragosa, El Mariachi pulls out a Sentinel Arms Stryker 12, along with the sawed off 12 gauge, that Buscemi described as "The biggest hand cannon I've ever fucking seen". El Mariachi used it to send several thugs flying unrealistically through the air, although it's worth noting the sequence is a fabricated ruse being told by Buscemi to unnerve his audience, so it's likely exaggerated on purpose. Sadly, it is the only time El Mariachi uses the weapon. A thug later in the film is seen using it, but very briefly.
Some thugs in the film use a Remington 870 with a sawed-down pistol grip, extended magazine tube, and a heat-shield similar to the gun used by Denzel Washington in Training Day.
Most of Bucho's (Joaquim de Almeida) men are armed with suppressed MAC-10 machine pistols that are most prominently featured in the Tarasco bar shootout, some with mock suppressors, some without. You will recognize the scene between El Mariachi (Antonio Banderas) and Empty Gun Man (Diego Sandoval) as inspiration for a similar scene between Agent Smith (Hugo Weaving) and Neo (Keanu Reeves) in The Matrix.
El Mariachi takes two M26 hand grenades from his guitar case on the rooftop, pulls the pins with his teeth (despite the 5lb pin pull) and then throws them at the two men on the street below. The grenades that are dropped appear to be rubber props, and notably still have their spoons attached. The grenades make a ridiculously large fireball instead of a more realistic explosion.
Some M67 hand grenades are seen in El Mariachi's guitar case. These are actually empty M69 training grenade bodies: this can be seen when he jostles the guitar case while grabbing the two M26s, and one of the grenades rolls over and shows the hole in its base.
Campa (Carlos Gallardo, who was El Mariachi in the original film) shows up to the firefight with a pair of guitar case machine guns. Robert Rodriguez has commented that the guitar case machine guns were built from MAC-10s. The sound effects used appear to based off the M134 minigun.
