According to information published here Iver Johnson Arms 9mm Carbine IJ did use leftover Universal receivers and parts. As I understand it, they acquired a quantity of forged steel receivers that required finish machining. I never mentioned that mine was a 9MM. Mine does indeed have a forged steel receiver. I don't know (or don't remember reading about it) if IJ used any of the Universal leftover receivers to build 30-caliber's or not. I know they converted some dual-spring's to single spring's....I own one.