Note: The title really is "Snatch." with a period at the end of the word. Don't ask us why the movie is titled that way, ask Guy Ritchie.
The following weapons were used in the film Snatch.:
Franky Four Fingers' accomplices during the jewel heist in Antwerp are all armed with second generation Glock 17 pistols.
A SIG-Sauer P228 pistol is used by the boxer John The Gun (Andy Till) to shoot himself in the head.
Heckler & Koch P7
When Vinny (Robbie Gee) threatens Bullet Tooth Tony (Vinnie Jones) he carries a Heckler & Koch P7 with black finish. It is implied that the gun, along with Sol's Heckler & Koch P9S are blank-firing 'replicas'. The prop itself, however, is a real P7 adapted to blank-fire.
Heckler & Koch P9S
Sol (Lennie James) uses a Heckler & Koch P9S to threaten Bullet Tooth Tony. The gun is also implied to be a 'replica', but they should not be able to fire full flash blanks out of the front of the barrel (like they do in the movie). The prop itself is a real P9S adapted to blank-fire, as there is no commercially-available blank replica of the P9S in real life.
IMI Desert Eagle Mark I
Bullet Tooth Tony (Vinnie Jones) famously carries a custom two-toned "Desert Eagle point-five-oh" with a stainless frame and black slide and barrel, with the flat surfaces on the slide polished. Cousin Avi (Dennis Farina) also tries to use the Desert Eagle in a later scene. The Desert Eagle used in the movie is the Mark I model (which was never available in .50 AE) and actually appears to be the .44 Magnum version, judging by the size of the bore.
In a flashback sequence, Charlie (Jason Ninh Cao) is shown shooting Tony six times with a stainless Walther PPK pistol, hence giving him the name "Bullet Tooth Tony". As Charlie shoots Tony six times before running out of ammunition, it can be inferred that it is chambered in .380 ACP
Smith and Wesson Model 681
Taurus Model 85
A Stainless Taurus Model 85 revolver with Bobbed Hammer is used by Tyrone and Vinnie throughout the film. The weapon is most noticeably seen in the hands of Vinnie when he and Sol attempt to rob the bookies. It is the first pattern Model 85 (Taurus has since changed the design of the Model 85 line).
Mossberg 500A Cruiser
It is seen briefly in the introduction, Boris the Blade pulls it out of his safe and cocks it. It is also seen on a table when Boris sells Franky Four Fingers his revolver, and later it is seen again in Boris' safe when Cousin Avi, and Bullet Tooth Tony raid his home. A similar shotgun also appears to be used by one of Mickey's friends, Darren, (Jason Flemyng) to shoot one of Brick Top's henchmen at the campsite.
Vincent (Robbie Gee) buys a compact 14" barrel version of the Franchi SPAS-12 shotgun for the heist of Brick Top's (Alan Ford) bookie. Sol fires the shotgun twice, first to blast a hole in the wall and then into the roof. As he throws a fit upon discovering that there is no money at the bookie's place, the teller takes it from him, firing it once before retreating behind the security screens. Notably, the bank scene is a perfect example of unnecessary cocking in films: Sol repeatedly cycles the semi-automatic weapon for emphasis, supposedly ejecting live rounds on the floor. Of course, considering that the scene lampoons the whole idea of a robbery, this can't be counted as a mistake or a goof, especially since blanks most likely wouldn't cycle the SPAS-12 action.
Unknown pump action shotgun
Various pump action shotguns are carried by Brick Top's thugs and the Pikeys, who use their weapons to ambush and wipe out Brick Top's men at the campsite.
Unknown double-barreled sawn-off shotgun
Two of the Pikeys use 12 gauge sawn-off double-barreled side-by-side shotguns to shoot Brick Top and his henchman, Errol (Andy Beckwith).
AK-74M with a GP-30
Boris 'The Blade' Yurinov fetches an AK-74M assault rifle with a GP-30 grenade launcher and magazines taped 'jungle-style' from his home after escaping capture and being hit by a car. He confronts Avi, Sol, Vinny, and Tyronne with it in a nearby bar, but never gets a chance to use it, as he is gunned down by Tony shortly after his arrival.
Boris 'The Blade's' gun collection
Boris 'The Blade' Yurinov has a collection of weapons which is shown three times during the movie: first when he is selling the S&W 681 to Tommy, when he returns a revolver to Franky Four Fingers and later when Cousin Avi and Bullet Tooth Tony break into his secret cache to look for the diamond. Feel free to ID what weapons are in there.