The following weapons were used in the film The Guard:
Handguns
Smith & Wesson Model 686
Liam O'Leary (David Wilmot) uses a Smith & Wesson Model 686 during the confrontation with Garda Aidan McBride (Rory Keenan). He then uses it to hold Garda Sergeant Gerry Boyle (Brendan Gleeson) at gunpoint when attempting to eliminate him at his house.
Glock 19
Sergeant Gerry Boyle (Brendan Gleeson) uses a Glock 19 in the final shootout at the end of the film. A Glock 19 can also be seen in the car trunk full of confiscated weapons.
Unknown Beretta
An unknown variant of the Beretta 92 can be seen in the car trunk.
Unknown Revolver
An unknown revolver can be seen in the car trunk and is right above the Type 56-1.
The cocaine smugglers use Colt Police Positives during the final shootout near the end of the movie. Cornell later takes one from a slain cocaine smuggler and wields it akimbo with his SIG-Sauer P226.
Beretta 92FS
At least one cocaine smuggler uses a Beretta 92FS during the final shootout. In a continuity error, Francis Sheehy (Liam Cunningham) uses a Beretta 92FS instead of a stainless Taurus PT92.
Taurus PT92
Francis Sheehy (Liam Cunningham) uses a stainless Taurus PT92 during the final shootout. In a continuity error, the pistol is instead the Beretta 92FS. The Taurus can be distinguished by its trigger guard.
Cobra Big Bore Derringer
When Eugene reports to Sergeant Boyle about a mysterious duffel bag, Eugene can be seen carrying a Cobra Big Bore Derringer (a modern pistol based on the Remington 1866 Derringer) before being relieved of it by Sergeant Boyle. It is also used by Sergeant Boyle (Brendan Gleeson) during the confrontation with Liam (David Wilmot). It can be noted that the Derringer is inaccurately described as the weapon that was used to assassinate Abraham Lincoln which is not possible as the pistol in question was not made until 1982. The pistol on which it is based (and in this case likely standing in for), the Remington 1866 Derringer, was also not invented at the time being released in 1866. The actual weapon used during the assassination was a Philadelphia Derringer, however the confusion could be caused by both guns having the word "Derringer" in their names.
Walther P38
Although it does not make an appearance in the film, the Walther P38 can be seen on several promotional posters of the film.
Agent Everett (Don Cheadle) uses a Zastava M70B1 given to him by Sergeant Boyle to provide covering fire for him as he advances to the cocaine smuggling boat. A non gun replica of the AK replaces the Zastava during the part where Sergeant Boyle rests the AK against a concrete wall.
Norinco Type 56-1
When Colum Hennessey (Pat Shortt) shows Sergeant Boyle a car trunk full of confiscated weapons, a Norinco Type 56-1 can be seen in the car trunk. During the movie, a duffel bag full of Type 56-1s is discovered by Eugene and confiscated by Sergeant Boyle.
Armalite AR-18
In addition to the Norinco Type 56-1, an Armalite AR-18 can be seen in the car trunk.
Non Guns
AK-47 Non Gun
A non gun replica of the AK-47 replaces the Zastava M70B1 in the scene where it rests against a concrete wall during the final shootout at the end of the film.