Yes, to accommodate the factory patented round butt-to-square conversion stocks.
Photo credit: handejector
Began in 1917 and used on the .32 and .38 Regulation Police Model I frames until the Model of 1953, and the .22/32 Heavy frame Target in the early 1920s.
Replaced by the true sq grip frame with sq Magna stocks on the Models of 1953 New I frames; same size as the J frame .38 Chiefs Special Baby Chiefs and Mod of 1953 Chiefs:
Photo courtesy of Terry C