quote:

Originally posted by Stonecreek:
Madrid:

I take it that you are loading .308 Winchester (7.62 Nato)?

The ring you see is quite normal and represents the point at which the case head/body is thick enough to resist expanding against the gun's chamber walls. The thinner brass ahead of this ring expands until it is constricted by the chamber walls, then when you run it into the resizing die (you call it a "mold"), the die reduces it back to a standard maximum diameter. The brass below this ring is not touched by the die because it has not expanded enough to exceed a pre-determined maximum standard diameter. This mark is often called the "pressure ring".

I am unsure of your reference to a ".307" shell holder. At any rate, the die (mold) should not normally be screwed all the way down against the shell holder, but rather screwed only so deep as to resize the brass enough that it easily re-enters the gun's chamber. Sizing any further may creat excessive headspace (cartridge significantly shorter than the chamber), which will cause work-hardening of the brass and cause it to fail due to the head separating at the pressure ring within in a few firings.

quote:

Originally posted by Stonecreek:
Madrid:

I take it that you are loading .308 Winchester (7.62 Nato)?

I am unsure of your reference to a ".307" shell holder. At any rate, the die (mold) should not normally be screwed all the way down against the shell holder, but rather screwed only so deep as to resized the brass enough that it easily re-enters the gun's chamber. Sizing any further may creat excessive headspace (cartridge significantly shorter than the chamber), which will cause work-hardening of the brass and cause it to fail due to the head separating at the pressure ring within in a few firings.