The Border Patrol used the 158 gr. JSP .357 cartridge up until the early 80's. The thinking was that the service wanted a hollow point round that penetrated less. The idea of dubbing a hollow point round a "controlled expansion round" and making it a .38 SPL was that it could be more easily sold to the (not so law enforcement thinking) higher ups in the Immigration and Naturalization Service who were the parent agency of the Border Patrol at the time. It was thought that the higher ups would have been appalled by officers carrying "dum dum" rounds. After a couple of shootouts where the 110 gr. .38 SPL +P+ "controlled expansion" round didn't measure up to it's expectations, displayed in tests, the round was dropped from service. Having broken the hollow point wall, the service adopted the 125 gr. JHP .357 round which served it's purpose until the USBP adopted semi-auto pistols and the .40 S&W cartridge.