Chase (Linden Ashby) uses an SA80/L85A1 while perched up on the "Eiffel Tower" in Las Vegas. It is fitted with a Aimpoint CompM2 red dot scope instead of the typical SUSAT scope.
Carlos (Oded Fehr) uses a PM-98 during the upgraded zombie fight in Las Vegas before running out of ammo and discarding it. It had an attachment under the barrel to set your hand on (which can also be equipped with tactical flashlight or lasersight) and a retractable buttstock. The PM-98 is a modified version of PM-84P GLAUBERYT made by Polish Fabryka Broni Łucznik Radom.
Claire (Ali Larter) uses a Glock 17 during the Vegas zombie fight. An Umbrella soldier also has one in his ankle holster, which he tries to shoot Alice with. Unsurprisingly, the soldier's pantleg is not large enough to cover the weapon, and during the fast cut of his draw, the cuff is shown tucked between the pistol and his leg.
When the super zombies try to break into the cab of the truck, K-Mart (Spencer Locke) uses what appears to be a Mossberg 500 shotgun to blow out a hole in the head of one of them.
As in Resident Evil: Apocalypse, Alice carries a Mossberg Compact Cruiser in her arsenal. She uses when fighting off the super zombies in Las Vegas. As in Apocalypse, she fires it one-handed. The weapon first appears about 8 and a half minutes into this film strapped to Alice's back in a cut-off commercial camo case as she pulls up to the TV station KLKB. Possible images of prop of weapon shown [here][1].
Claire Redfield (Ali Larter) uses a Mossberg Model 464 to try and kill a zombie on top of Mikey. The sound effect doesn't follow every time Claire cocks the weapon. It seems like for every 2 shots, we see her cock once, but when she first it off screen, we don't hear her cock again for the next shot before we see her cock again. The Mossberg Model 464 is a reproduction copy of the Winchester Model 1894 produced by Mossberg, and boasts an already drilled & tapped scope mount.
Carlos has 2 Heckler & Koch USP-9s , with stainless steel slides. He loses one of them under the bus. In the next shot when we see him crawling under the bus, his remaining USP apparently was switched with a Taurus PT92AF.
Carlos tells a survivor to lock and load his Winchester Model 1300 shotgun when they leave the crow infested motel. (It appears to be a Winchester due to the large burnt sienna cocking pump.)
