This Harrington & Richardson manufactured second variation black synthetic trigger guard is for the model 750 Pioneer bolt action rimfire rifle with the Monte Carlo style second variation stock which has hole spacing of 2 7/16" apart and is in very good condition with normal wear.  (file photo)

Note: Harrington & Richardson model 750 Pioneer bolt action single shot rimfire rifles with the following serial numbers have been observed with this part: N.S.N.