I have shot all kinds of .38's thru my Henry.357 and have some FTF but not many. I follow the suggestion from the Henry board at the end of a shooting session of .38's to fire two or three rounds of .357 to clear any build up from the lighter rounds configuration. Seems to work. What Henry tells you is what they have to tell you to protect themselves from law suits. The real world is different. If you haven't gone to the Henry board yet, do so. There a few members who are fighting cancer and they are survivors also. The .com board not the .org board.