My own personal preference when starting a new pistol shooter is the revolver, with 22 rimfire or 38 spl. target loads. The revolver is easier to load, easier to operate (no safeties, slide locks, no torn thumb if your hand is not place correctly), and only having 5 or 6 round also tends to focus attention on the sights. And smaller groups are a lot more fun for new pistol shooters than a shotgun pattern from an auto. Also that GP100 is a very strong pistol and can last several life times with proper care.