Tom Threetoes
Marksman
The inner part is the collet and the bottom of that piece is what needs to be shortened the same amount that your cases are shortened, otherwise the case neck won't go in far enough for the collet to squeeze it. For a long time I thought both inner and outer parts needed shortened but I was't doing my home work. I haven't worked on mine yet but I think I'll take the inner part out and have my friend with a lathe shorten it as there isn't much room for error. (Edited to add) Sorry Mike, I didn't know you had posted a reply. You are certainly more qualified to respond than me!
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