The spring that was in my old frame was barely noticeable located towards the bottom of the hole the take down pin fit into. When the slide was open the pin would be loose and not have any tension from the wire. Today I fired with the new frame. The spring is more in the center of the hole and when the slide is open the take down pin has a little bounce to it from catching on the spring. I don't know if it is a different take down lever. I fired 200 rounds without a misfire or the take down lever coming loose. However,I did loose the small gray laser button off of the right side. I fell real comfortable with the gun now and once I get the button replaced I will be a totally happy camper. Now to choose a holster-any suggestions?