2 questions. First, I am looking closely at 6mm PPC brass for my 9x39 project. It has all the attributes I need in a case, and it will save me fire-forming the brass, which to me is too costly and time-consuming to justify. Thinking about it, my 9x39 could be described as a 9mm PPC due to the case design and heritage (based on Russian 7.62x39 cartridge). The PPC gives me greater powder capacity since it is wider at the shoulder. If this works, it will provide a relatively affordable source of brass for my project. I was looking at 6.5 Grendel brass but it is more expensive than the 6mm PPC I've found. It would be better because it is already .5 mm closer to 9mm, meaning less stretch on the mouth. I really don't think 6mm > 9mm will be an issue for me.
I have found a "case resizing die" but I don't understand it. Here it is:
Does this resize the case to be WIDER at the shoulder? Or does it resize the mouth from .311 to 6mm/243 size? The description implies it resizes the case, but I can't see that in my mind. Does it force a ram down the mouth to straight-wall the brass, then size the neck?
Can someone explain how I would go about sizing the tapered 7.62x39 cartridge to the straight-wall 6mm PPC size WITHOUT fire-forming the brass?
Second Question. 6mm PPC brass sources. I've found this source for $40/100 and I'm wondering if it may be found cheaper someplace else:
Any other sources?