For the S&W 642, the Smith & Wesson Company told me I have a square butt, meaning it is 1 1/4" or wider at the base of the stock. I ordered and returned an Ebay Hogue which they said would fit , but didn't fit. I am now looking at Packmayr which DOES make a grip, square butt, for the 642 and appears to have a hardy grip for recoil issues shooting the 38 +P and regular 39 Special. Square butts are rare and can be a frustrating search.