Connor (Sean Patrick Flanery) and Murphy (Norman Reedus) McManus use pairs of suppressed Beretta 92FS pistols when dispatching various criminals in the film. They also give Rocco (David Della Rocco) a pair of 92FS' when they recruit him to their team.
Due to a continuity error, the MacManus brothers' Beretta 92FS pistols become Brazilian-made Taurus PT92AFs in several scenes. They are distinguished by their frame mounted slide stop safety instead of the slide mounted decocking safety found on the Beretta 92FS.
The assassin (Markus Parilo) also uses a pair of stainless sound suppressed PT92AFS' to kill the family in the flashback as Rocco explains why they should kill him. Il Duce (Billy Connolly) also uses a PT92AFS when facing off with the brothers and Rocco outside the house.
While summing up the shootout in front of the house, Agent Paul Smecker (Willem Dafoe) fires his Glock 26 pistol into the air, which is something a real FBI Agent would never do. Although, admittedly, Smecker isn't what someone would call "all there". Plus this might just be in his head, rather than actually taking place. (This seems likely since none of the cops look nearly startled enough to have witnessed an FBI agent firing his gun into the air in the middle of a suburb.)
If you listen closely you can hear in the background an unintentional discharge called in over a police radio.
Ivan Checkov (Scott Griffith) carries a custom Desert Eagle Mark VII. The weapon appears to be built up from both Chrome and Blued finish models, with some features gold plated, and a gold hammer and sickle inscribed below the bore, with a red Soviet star on top of the slide. Agent Paul Smecker (Willem Dafoe) refers to the bullets found at the scene as being ".50 caliber", yet both guns used are actually .44 Magnum.
Error creating thumbnail: File missingA custom Magnum Research Desert Eagle Mark VII built by Movie Armaments Group (MAG) for The Boondock Saints. The weapon pictured here is the actual screen-used weapon from the film; this image can be found on MAG's Instagram account. Note the "Desert Eagle .44" stamp on the slide, as well as the Soviet star on top of the slide.Error creating thumbnail: File missingAnother view of the screen-used Desert Eagle Mark VII from the film; note the gold hammer and sickle on the front of the barrel, as well as the ".44" stamp, contrary to the movie dialogue which indicates that the gun is a .50-caliber.Error creating thumbnail: File missingIvan holds his Mark VII Desert Eagle on Connor, his with a chrome slide, a blued barrel and frame, and a gold plated safety. Note the red star on the slide.Error creating thumbnail: File missingHere, the bore appears to be a .44 and under the barrel is a gold plated symbol of the Communist Party, the hammer and sickle.Error creating thumbnail: File missing"I hope your conscience is clear, Irishman!" Ivan holds his Desert Eagle on Murphy before Connor drops a toilet on him from the roof.Error creating thumbnail: File missingMurphy staring down the barrel of the Desert Eagle.Error creating thumbnail: File missingWhen Agent Smecker investigates the crime scene afterward, he finds a bullet in the dumpster, yet here you can see he misses the dumpster by a lot.Error creating thumbnail: File missingThe brothers trade the two Desert Eagles to the weapons dealer so they can take guns.
IMI Desert Eagle Mark XIX
The other of the two Russian mobsters carries a Desert Eagle Mark XIX which, like his partner Ivan Checkov's (Scott Griffith's) gun, is a two-tone model. Unlike Checkov's gun, however, his Desert Eagle lacks either gold-plated controls or the hammer and sickle markings on the slide/barrel.
Error creating thumbnail: File missingPara Ordnance P-14 - .45 ACPError creating thumbnail: File missingI1 Duce armed with an Taurus PT92AFS, Para Ordnance P-14, Smith & Wesson Model 629, Smith & Wesson Model 686, Smith & Wesson 5906, and a Para Ordnance P-10.Error creating thumbnail: File missingIl Duce draws the Taurus PT92 and the Para-Ordnance P-14. Interestingly enough, he does not keep the P-14 in "Condition One" while holstered, which would greatly slow his readiness to fire the weapon. (Also note that the entire firefight supposedly took place in seconds, so having the hammer down would have slowed his draw significantly.)Error creating thumbnail: File missingIl Duce wielding a Para-Ordnance P-14 in his right hand.
Il Duce (Billy Connolly) uses a Smith & Wesson 5906 as one of his six guns during the shootout outside the house. A thug during the poker game is also seen using one.
A Beretta 92FS Inox with a custom muzzle brake is seen on a wall in the dealer's armory. The Beretta in this scene was originally customized for the TV series Once A Thief, where it was carried by Nicholas Lea as his sidearm.
Agent Paul Smecker (Willem Dafoe) uses a Walther P5 Compact fitted with a suppressor while dressed in drag to kill men in Papa Joe Yakavetta's (Carlo Rota) house in an attempt to save the brothers. It features gold plated parts and is the same gun used by Claire Danes used in Romeo + Juliet (albeit minus the ivory grips from that film); it was also used in the same configuration in the final episode of the TV series Once A Thief.
Papa Joe Yakavetta's (Carlo Rota) henchmen are seen with Custom M1911A1 pistols in their shoulder holsters. Both of the brothers are seen drawing them on Il Duce when he confronts them in the house. Before the confrontation at Yakavetta's house, one of these same 1911s is also seen briefly in the hands of one of the Russian thugs who is killed during the brothers' first mission at the hotel.
Several Glock 17s are seen in the dealer's armory and several thugs use them in the film. They are also the sidearms of the Boston City Police Department.
Rocco (David Della Rocco) carries a snub nosed Colt Python with a stainless finish and most notably uses it to kill the three men in the diner. Some people are inclined to believe Rocco uses a Colt Diamondback instead of a Python because Det. Greenley (Bob Marley) claims they recovered .38 slugs at the crime scene. One should note that a .357 Magnum and a .38 Special round are dimensionally exact in diameter (but not length), so the bullet head would be .357 regardless of which round was used.
Error creating thumbnail: File missingNickel plated Colt Python with 2.5 inch barrel - .357 MagnumError creating thumbnail: File missingConnor and Murphy mess with Rocco by making him think they are going to kill him. They then pull out his Colt Python snub.Error creating thumbnail: File missing(Connor):"Jeez, it's a fuckin' six-shooter!" (Murphy):"There's nine bodies, genius." (Connor):"What the fuck were you gonna do, laugh the last three to death, FUNNY MAN?!"Error creating thumbnail: File missingRocco tells his girlfriend he will kill himself right there and then if she can even recall the name of her recently deceased cat. Or even its color.Error creating thumbnail: File missing"Shut your fat ass, Rayvie! I can't buy a pack of smokes without running into nine guys you fucked!"Error creating thumbnail: File missingRocco kills a mobster in the diner by firing his Colt Python through his jacket.Error creating thumbnail: File missingRocco shoots the other mobster and we see the full effect of a .357 round. If you look close, you see he fires the gun early as he swings it at him, likely done to fire blanks safely at close range.Error creating thumbnail: File missing"FUNNY, FUNNY, FUNNY!" Rocco kills the diner clerk for not telling him he was set up.Error creating thumbnail: File missingRocco holds his Colt Python on the priest in the confession booth as he listens to the confessions of Agent Smecker.
Papa Joe Yakavetta (Carlo Rota) also uses a Colt Python, his with a blued finish, a 6" barrel, and rubber grips, later in the film. Some people claim it is a Colt Anaconda due to its seemingly large size, yet the Anaconda was never released in a blue finish, only stainless steel.
Il Duce (Billy Connolly) wields a Smith & Wesson Model 629 Snub as one of his six guns during the shootout outside the house. While originally thought to be a Model 66 revolver, the muzzle diameter of the gun is clearly larger than the 686 Snub in his right hand, ruling out the gun being a .357 Magnum.
Il Duce (Billy Connolly) wields a Smith & Wesson Model 686 with a 3" barrel as one of his six guns during the shootout outside the house. Chappy (Kevin Chapman), a thug in Papa Joe Yakavetta's house is also seen using one.
Det. Greenly (Bob Marley) has what appears to be a Smith & Wesson Model 19 Snub Nose with aftermarket grips in his shoulder holster, which isn't seen clearly in the widescreen version of the film, so a full screen shot is used.
Il Duce (Billy Connolly) uses a Franchi PA3/215 with the stock removed during the final scene in the courthouse when he and the brothers execute Papa Joe Yakavetta (Carlo Rota).
As the prison guards escort Il Duce (Billy Connolly) out of prison for his parole, a few of the guards are armed with what appear to be High Standard Flite King shotguns.
An M16A1 rifle fitted with an M203 grenade launcher is seen in the armory. According to a post on Movie Armaments Group's (MAG's) Instagram account, the weapon is actually a Harrington and Richardson-manufactured M16A1 with an AAI XM203 grenade launcher, an early prototype version of the M203.