The following guns were used in the film Reign of Fire:
Ulriks Mauser Tyrannosaurus Rex .577 Nitro
Quinn Abercromby (Christian Bale) keeps an Ulriks Mauser Tyrannosaurus Rex or T-Rex rifle in the massive .577 Nitro cartridge and is seen with it several times in the film, most notabley when he faces the Male Bull Dragon and fires at it. Like the .600 Nitro double rifle in The Lost World: Jurassic Park, this gun is an expensive, rare gun customly crafted by expert gunsmiths. The gun is said to have such vicious recoil and overkilling firepower, even hunters in Africa only keep it as a back-up gun incase of a charging animal. Even with such immense firepower, the rifle mananages to do little more than make the dragon mad. When looking closely at the front sight, it appears they used more than one rifle in the film as the front sight changes in some shots.
Shorty Mossberg 500
Denton Van Zan (Matthew McConaughey) uses a pistol gripped Mossberg 500 with a super-short barrel and a finger-grooved foregrip on the pump as his main weapon throughout the film, keeping it slung at his hip like an over-sized sidearm.