There's 2 revolver only matches Harry Reeves & Distinguished Revolver .
Harry Reeves you can shoot anything 32 caliber centerfire or larger . Barrel length including cylinder not more than 10 inches . Trigger pull not less than 2.5lbs unless 45 cal then it can't be less than 3.5lbs . Any sights allowed as long as it does not project an image on the target . Open sights may be adjustable but can not be over 10 inches apart apex to apex . All safety devices must operate as designed . No assisted / programed triggers . Any safe load ammo is permitted . 10 shots slow fire @ 50yds , 10 shots timed fire @ 25yds , 10 shots rapid fire @ 25 yds . Many use custom built guns with aftermarket barrels .
Distinguished Revolver must use a factory manufactured revolver with no external / internal modifications except grips but they must be a mirrior image of each other ie no custom target grips . Must be capable of chambering & firing a 158gr RN or SWC 38 special cartridge . Minor trigger stoning allowed for a crisper sear release & not less than 2.5lb pull . More restrictions also but this gives you an idea . You can use factory or reloads but must be 38 special 158gr RN or SWC any safe load . Again 10 shots @ 50yds , 20 shots @ 25yds .
Google NRA match rules & look for Outdoor Conventional Pistol rules . They'll tell you al you need to know
