Don, as far as I have been able to determine any gun, rimfire, shotgun or centerfire manufactured in a given year has an identifier (N + letter for NEF and H + letter for H&R) except some much older guns that had only one letter before the numerals in the serial number. That means a receiver with the NR prefix was manufactured in 2001 but could have been either a rimfire, shotgun, or centerfire rifle. A check of the receiver of a knowledgeable handiholc should be able to determine which it was, short of that the factory still remains the best source of info, but even the experts read from the wrong line once in a while and we all make mistakes, good luck....<><.... :grin: