Okay, there is a lot of yes, and no, One member said just remove the flag, I just had to try it on one of my guns, M-617, 6 inch, It was not hard to remove the flag, Except for a little spring flying across the room, took me about a hour to find it in the last place I looked, down in a box of ammo, and junk, but anyway it took about a 1/2 # off my double & single action trigger pull, and fills more smooth like my older Smith, going to try it at the range maybe Monday, I may be removing the flag from my other M617 & M637, Hope I will not be needing any warranty work. will I need to put the flag back in ?