In "LA X Part 2" (S6E02), Kate takes a SIG-Sauer P226 from the Deputy U.S. Marshal Edward Mars and pulls it on the driver of the taxi with Claire in it.
Walther P38s are seen multiple times over the course of the series. In "What Kate Does," Kate steals a P38 from Aldo. In "Lighthouse," Kate almost shoots Jack with the same P38. In "Sundown," Kate may have given the same P38 to the Others. In "The Candidate" (S6E14), Charles Widmore (Alan Dale) fired a P38 into the air. Please refer to the Discussion section for a more detailed listing of the P38's use in Seasons 2-6.
The Remington 7400 rifle is one of the rifles seen carried by one of the followers in "LA X (Part 2)" (S6E02). Jack (Matthew Fox) holds the Remington Model 7400 rifle in "Everybody Loves Hugo" (S6E12).
AKM rifles were commonly seen in both flashbacks and on the island itself. A large collection of AKM rifles is seen in the armory housed in the bunker known as "The Swan". The majority of the AKM's found here were loaded with 20 round magazines.
The Ruger Mini-14 is a prominently featured rifle in the series. In several episodes, the rifle is seen in the hands of "The Others". The characters seen carrying the Mini-14 include Sayid (Naveen Andrews), Jin (Daniel Dae Kim), Sawyer, Kate, and Lapidus (Jeff Fahey). In Season 6, numerous followers of Jacob are seen with these rifles. Another notable use by these followers is in Season 6's premiere "LA X (Part 1)" (S6E01), where Bram (Brad William Henke) tries to shoot "Locke"/Man in Black, but the bullets bounce off.
The M1 Carbine is another one of the common weapons used on the island. In Season 6, the weapon is seen carried by Claire Littleton (Emilie de Ravin) and Illana (Zuleikha Robinson).