Kinda new to revolvers and have a question. Do all models have the pin that goes into the rebound spring? I put back together same as I tore it apart but I can hear that pin clanging around in assembly. Is that normal? I have seen many videos and almost none show that pin, just the spring. And what purpose does the pin inside the spring do? I do see that it is rounded on one end and on mine the other end is cut straight. It's 11/16" long.

Thanks

Actually that pin has also been used in some of the Performance Center K and L frames, so it's not exclusive to the N frame. However, it is standard to all of the N frames that I am aware of and probably the X frames as well.

As noted it's primary purpose is to provide a trigger stop. However, IMO it also helps reduce buckling of the rebound spring inside the bore of the rebound slide. As a result it's been my experience that revolvers with this pin have smoother DA triggers with less stacking.

Now a warning. These pins are position critical. If you look closely you'll note that one end is sort of pointed. If you find that your trigger locks up solid with the revolver held in certain positions you'll need to flip that pin end for end. BTW, I have a vague memory that the pointy end goes against the pin for the rebound slide but don't count on that memory. To tell the truth I got it wrong so often installing that pin that I've made all of mine "double ended" so they cannot be installed wrong.

This is my goto video for detailed disassembly.

Smith and Wesson Model 29 .44 Magnum Detailed Disassembly - YouTube