After Jackie Brown, Tarantino didn't bring a movie to theaters for six years when he went in a completely different direction with a two-part love letter to over-the-top Kung Fu movies and spaghetti westerns. Kill Bill: Vol. 1 was released in 2003 and Vol. 2 followed in 2004. The first movie is a straight up martial arts film starring Uma Thurman as The Bride, a wronged woman who swears revenge on a team of assassins and their leader, Bill, after they try to kill her and her unborn child. Her revenge quest takes her to Japan where she takes on the Yakuza in Tokyo. As evidence of how much of a departure the movie was for QT, it features an anime sequence created by Production I.G. Vol. 2, which was shot concurrently with Vol. 1, is more of a western with a few more guns and fewer swords, that sees The Bride continue her revenge mission against the "Deadly Viper Assassin Squad," (Lucy Liu, Michael Madsen, Daryl Hannah, and Vivica A. Fox) which is an awful lot like the Fox Force Five TV show that Uma's character Mia Wallace describes in Pulp Fiction. The films were the highest grossing of Tarantino's career at the time. The Bride / Beatrix Kiddo

The Bride with her customized stainless Star Firestar pistol.
The Bride with her customized stainless Star Firestar pistol.imfdb.org

While the protagonist of the kung fu anthology, The Bride, doesn't use a gun in the first movie, in the second—which has more of a western flare—she has a sidearm in addition to her Hatori Hanzo sword that she retrieves from Budd.

If it looks like an odd 1911, that's because it isn't one. She carries a stainless Star Firestar pistol in .45 ACP, which isn't a 1911-platform pistol at all, but it is a hammer-fired single-action only pistol with a manual thumb safety and an all-steel construction with a 7+1 capacity. The biggest design difference from a 1911 is the Firestar is lacking a grip safety.

It has an overall length of 6.7 inches and a 3.8-inch barrel. The Bride's gun looks quite a bit longer because hers has a custom extended barrel and slide.

The Bride's custom pistol includes an extended barrel and slide.
The Bride's custom pistol includes an extended barrel and slide.imfdb.org

She wields the pistol most notably when she's attacked by an assassin in her motel room and near the end when she finally confronts Bill (David Carradine) in his home, along with her sword.

Bill

Bill fires his colt at Beatrix and we see a closeup of a firing pin striking the primer of a .45 Long Colt cartridge.
Bill fires his colt at Beatrix and we see a closeup of a firing pin striking the primer of a .45 Long Colt cartridge.imfdb.org

In the first film, we only get an out of focus view of Bill himself, and his gun, but we can tell its some kind of Colt SAA reproduction. In the second film, we see that it is a customized EMF Hartford 'Pinkerton' revolver with a bird's head grip.

In Vol. 1, we see it from the muzzle and then get a CG closeup of the inside of the gun as the firing pin hits the primer on a .45 Long Colt round, the one that's fired into The Bride.

Bill's Colt SAA
In Vol. 2 we get a better look at Bill's gun, which has some kind of compensator attached to the muzzle.imfdb.org

In the sequel, Bill seems to be carrying the same gun, though now it has some kind of bizarre muzzle brake or compensator attached, though there don't seem to be any ports.

Other Bad Guys

Budd with his 12 gauge.
Budd with his 12 gauge.imfdb.org

The Bride pays a visit to Budd's (Michael Madsen) trailer and eventually retrieves his Hanzo sword after blinding Elle Driver (Daryle Hannah) for killing the sensei they shared—but not before taking two loads of rock salt fired from Budd's 12 gauge double barrel shotgun to the chest. The gun looks to be a Remington but we can't be sure.

Karen Kim with her Remington 870.
Karen Kim with her Remington 870 shotgun.imfdb.org

The assassin Karen Kim (Helen Kim) uses a cut down and sawed off Remington 870 pump action shotgun

A sawed-off Remington 870 is used by the assassin Karen Kim (Helen Kim) when confronting Beatrix in her hotel room.