Hitman Jules Winnfield (Samuel L. Jackson) carries a 9mm Star Model B throughout the film. Some audiences have been confused due to the Model B's visual similarity to the .45 ACP 1911 series (like Vincent's Auto-Ordnance M1911A1) and some movie critics have (wrongly) listed Jule's reference to his gun as "Mr. 9mm" as a goof, but as the Star Model B is a 9mm gun, it is not a mistake.
Marsellus Wallace (Ving Rhames) pulls a Smith & Wesson 4506 with adjustable sights after surviving being struck by Butch's white 1980 Honda Civic at a stoplight. Butch (Bruce Willis) also is seen with the 4506 during the following scuffle with Marsellus.
Taurus Model 689
"Man #4" (Alexis Arquette) bursts out of the bathroom with a Taurus Model 689 chambered in .357 Magnum with a custom ported barrel. Man #4 empties the revolver but despite the close range, neither Jules nor Vincent are hit. Afterwards, they remark on the size of the man's "hand cannon" and Jules comes to believe that God deflected the bullets. (Thanks to Phoenixent, who confirmed that the revolver was a Taurus Model 689.)
Submachine Guns
MAC-10 (Suppressed)
When Butch Coolidge (Bruce Willis) returns to his apartment to retrieve his father's watch, he finds a suppressed MAC-10 on his kitchen counter. The MAC-10 belonged to Marsellus Wallace, who left it on the kitchen counter while going out to get himself and Vincent some breakfast - This being confirmed in the trivia track (bonus feature) on the Collector's Edition DVD of the film released in 2002. In the script, the weapon is described as an Sa. Vz.61 Skorpion.
Shotguns
Remington 870
Maynard (Duane Whitaker) pulls a Remington 870 with an extended barrel and magazine tube to end the fight between Marsellus and Butch. Marsellus is also seen with the Remington.
Trivia
Beretta 92FS Inox
What appears to be a Beretta 92FS Inox appears on the poster for the film, though no such gun is ever actually featured in the film itself.