Gameflyer450, I've owned my reign for about a year in .25 cal. The two best pellets for me are the H&N Field Target Trophy 19.91 Grain and the Predator Polymag 26.0 Grain. If you're hunting Iguana, either will work fine. Just shoot, shoot, shoot. Each gun takes 200-500 rounds to 'season in' and polish the fine burrs of manufacturing out of the barrel. Once it's seasoned in you'll know it. Enjoy shooting!