It is a steel piece directly about the forcing cone on the barrel, where it protrudes through the frame. It is placed there to prevent flame cutting of the top strap. Very necessary on scandium framed revolvers.

A 1000 round count isn't set in stone, but it is a very accurate number. Most that own the super lightweight revolvers will never get close to the 1000 rd. count. Alot of wear can be attributed to what kind of ammunition, or powder that you are using, if handloading.

H110/Win. 296 powder seem to be major contributors to this. 2400 powder, not so much. I have about 1800 rounds through my 329PD, with stiff loaded 240 grainers over 2400. No marks, no etching.