The Model 1896 was designed to use 38 Double Action hard rubber stocks, which then became the standard for the Model 1903 and several successors. There are a few pre-WWII I Frame stocks that will not fit a standard I Frame, like those found on Regulation Police revolvers and some 22-32 HFTs. Those had butt-frames with a step on the back leg of the frame and took a special set of stocks to fit them. Roy stated that all stocks on 1896s were hard rubber and could be either round butt or extended square butt targets.