In regards to the single-action revolver in the holster in pictures from the set of Tremors 5. (Michael Gross) can be quoted saying the script called for a Colt Single Action Army but what they ended up with was a replica in a "Cattleman's" configuration with a slightly longer barrel that Burt derisively calls a "pop-gun." Naturally, though, he proceeds to "do what he can with what he's got. If I had to guess presently based on what Michael Gross said, its a Uberti Cattleman with 5-1/2" Barrel.
Burt is somewhat concerned and disappointed when he discovers he is forced to hunt Graboids with a .303 Caliber BSA rifle, Burt uses it a few times throughout the movie.
While stateside, in Perfection Valley, Nevada. Burt hosts an episode of a survivalist reality show and totes around this presently unknown bolt-action rifle.
Travis (Jamie Kennedy) easily convinces Burt (Michael Gross) that he needs to go to South Africa too, giving him the HK91 in exchange. The HK91 has a special place in Burt's heart as it was the gun Heather Gummer requested from Burt when she left him.
The Protecta is used by Den Bravers (Ian Roberts) when he goes on a rescue mission.
Armsel Protecta, 12" barrel - 12 gauge
Machine Guns
FN MAG 58
Both Burt (Michael Gross) and Travis (Jamie Kennedy) use a FN MAG belt-fed machine gun in the film, it appears to have a synthetic buttstock and was given to Burt by Den Bravers (Ian Roberts).