Hitman Jules Winfield (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 M1911 (like Vincent's Auto Ordnance 1911) 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.
When Butch Coolidge (Bruce Willis) returns to his apartment to retrieve his father's watch, he finds a suppressed MAC-10 in 9x19mm Parabellum on his kitchen counter. According to IMDb, 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 fact is also confirmed in the trivia track (bonus feature) on the Collector's Edition DVD of the film released in 2002.
Marsellus Wallace (Ving Rhames) pulls a Smith & Wesson 4506 (with adjustable sights and sight guard) after surviving being struck by Butch's (Bruce Willis) white 1980 Honda Civic at a stoplight. Butch also is seen with the 4506 during the following scuffle with Marsellus.
Maynard (Duane Whitaker) pulls a Remington 870 with an extended magazine tube to end the fight between Marsellus and Butch. Marsellus is also seen with the Remington.
"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.)
