Frank Castle (Ray Stevenson) uses twin stainless Beretta 92FS Inox pistols with extended mags and converted to full-auto (in the comics, the M1911 is Castle's pistol of choice, but it appears only briefly in the movie and is never used).
Beretta M92SB
Jigsaw's thug Pittsy (Mark Camacho) carries a Beretta 92SB), fitted with what appear to be pearl grips, which is later taken by Agent Budianski (Colin Salmon).
Beretta 9000S
Angela Donatelli (Julie Benz) keeps a Beretta 9000S for home safety, which she points at Castle, at first mistaking him for an intruder, and then recognizing him as the man who killed her husband.
Colt 1911A1 GI
The Colt 1911AI GI is the pistol of choice for the Punisher in the comics, but is never used in the film, only seen at the beginning being disassembled and cleaned by Frank.
Glock 17
Officer Saffiotti (Tony Calabretta) holds Castle up with a 3rd-Gen Glock 17 near the beginning of the film. Agent Budianski (Colin Salmon) does the same later.
Later, Carlos (Carlos Gonzalez-Vio) purchases another of these pistols from a gangbanger acquaintance (as part of Micro's unofficial "buy-back" program), then has it snatched away and shoved into his throat by Castle inside Micro's apartment.
Makarov PM
During the summit with Jigsaw, one of the bodyguards accompanying Cristu Bulat (David Vadim) draws a Makarov PM.
Frank Castle (Ray Stevenson) carries the Performance Center version of the Smith & Wesson Model 500 as one of his sidearms. He has at least two, one in stainless steel with extended ejector shroud, and a second with a supressed black barrel and a Knight's Armament RIS setup, flashlight, and laser. During the final confrontation, Jigsaw (Dominic West) relieves Frank of the weapon at gunpoint, empties four of the five rounds into Frank's bulletproof vest, then tosses the weapon back to him to "decide" how to use the last one.
Several members of the gangbangers also carry the weapon, some standard and some with scopes.
Walther P22
One of the guns on Frank's gun rack is a Walther P22.
Submachine Guns
Brügger & Thomet MP-9
During the mansion gunfight, a wounded thug crawls laboriously towards a dropped Brügger & Thomet MP-9, while Castle is gunning down several other thugs, only for Castle to almost-casually shoot him on his way out the door, just as the thug starts to raise it.
H&K MP5K
In one of the film's most promoted sequences, Frank Castle (Ray Stevenson) draws a pair of Heckler & Koch MP5K's from back holsters and unloads them while spinning upside down from a chandelier in the mansion gunfight. The weapons have satin nickel receivers, and the foregrips have been removed,making them true "machine pistols."
One of the FBI Agents with Agent Ross during his meeting with Jigsaw carries a Heckler & Koch MP5SD.
Rifles
AKS-74U
Several of Tiberiu's Russian thugs carry AKS-74U carbines during the final shootout.
Beretta CX4 Storm
Several of the Chinese Triad members carry Beretta CX4 Storm rifles during the final shootout.
Heckler & Koch G3A3
The Chinese Triads set out Heckler & Koch G3 rifles before the final shootout.
H&K G36C
Several Chinese Triads use Heckler & Koch G36C rifles during the final shootout.
Heckler & Koch G36K
The Chinese Triads set out Heckler & Koch G36K rifles before the final shootout.
Heckler & Koch SL8
Frank Castle (Ray Stevenson) uses a Heckler & Koch SL8 to snipe one of the members of Maginty's gang between the eyes, then to kneecap Maginty himself.
M4-type weapon
During the final assault, Frank Castle (Ray Stevenson) takes a custom M4A1-type carbine with KAC Quad-rails, a C-More red dot optic, an M4-2000 by Advanced Armament Corp suppressor, and a short version of the AG36 grenade launcher, which is really an Airsoft prop. It is referred to by the Armorer on the behind-the-scenes feature as an M4 with a short barrel. It appears to be a short-stroke piston upper of some type, but IMFDB has been unable to identify the specific make/model. (It is NOT a Heckler & Koch HK416 as some have speculated.)
When Jigsaw goes to terrorize the Donatellis, Ink ((Keram Malicki-Sanchez) carries a Franchi PA3 shotgun, which Jigsaw (Dominic West) uses to threaten the Donatellis and force Agent Budianski (Colin Salmon) to surrender. When Ink drifts into a back room, Castle kills him, takes the shotgun, and later uses it to blow Pittsy's head off.
Other
H&K AG36 Grenade Launcher
Castle (Ray Stevenson) apparently shortens a Heckler & Koch AG36 Grenade Launcher to make it lighter and perhaps handier in close quarters. Prop wise, this is an airsoft product called the AGX made by Madbull (a grenade launcher that can be mounted on any picatinny rail equipped rifle). They have been making reference to its use in the film for some time now.
He uses it towards the end of the movie, shooting some kind of air burst grenade (it explodes in mid-air).
M203 Grenade Launcher
After a member of the Maginty's gang is vaporized in midair, a stunned Maginty turns and sees Castle (Ray Stevenson) holding a smoking M203 grenade launcher, which he then switches for his Heckler & Koch SL8. Incongruously, the effects make the weapon seem like a guided missile launcher.
M4X Knife
Frank's combat/utility knife is used to perform his first kill of the movie, nearly decapitating mob boss Gaetano Cesare, before being plunged into the crown of another dining mafioso's skull.